/
usr
/
share
/
doc
/
python2-docs
/
html
/
library
/
/usr/share/doc/python2-docs/html/library
mkdir
upload
Name
Size
Mode
Actions
2to3.html
59507
0644
edit
dl
rm
abc.html
25826
0644
edit
dl
rm
aepack.html
14164
0644
edit
dl
rm
aetools.html
16389
0644
edit
dl
rm
aetypes.html
21021
0644
edit
dl
rm
aifc.html
25064
0644
edit
dl
rm
al.html
18672
0644
edit
dl
rm
allos.html
35297
0644
edit
dl
rm
anydbm.html
18124
0644
edit
dl
rm
archiving.html
10078
0644
edit
dl
rm
argparse.html
263616
0644
edit
dl
rm
array.html
31855
0644
edit
dl
rm
ast.html
38167
0644
edit
dl
rm
asynchat.html
33930
0644
edit
dl
rm
asyncore.html
40631
0644
edit
dl
rm
atexit.html
18455
0644
edit
dl
rm
audioop.html
34252
0644
edit
dl
rm
autogil.html
8733
0644
edit
dl
rm
base64.html
21862
0644
edit
dl
rm
basehttpserver.html
37441
0644
edit
dl
rm
bastion.html
11798
0644
edit
dl
rm
bdb.html
41395
0644
edit
dl
rm
binascii.html
22997
0644
edit
dl
rm
binhex.html
11309
0644
edit
dl
rm
bisect.html
24666
0644
edit
dl
rm
bsddb.html
28589
0644
edit
dl
rm
bz2.html
29048
0644
edit
dl
rm
calendar.html
41762
0644
edit
dl
rm
carbon.html
51998
0644
edit
dl
rm
cd.html
30033
0644
edit
dl
rm
cgi.html
55922
0644
edit
dl
rm
cgihttpserver.html
14026
0644
edit
dl
rm
cgitb.html
12263
0644
edit
dl
rm
chunk.html
15899
0644
edit
dl
rm
cmath.html
28365
0644
edit
dl
rm
cmd.html
29042
0644
edit
dl
rm
code.html
26959
0644
edit
dl
rm
codecs.html
118258
0644
edit
dl
rm
codeop.html
15898
0644
edit
dl
rm
collections.html
147647
0644
edit
dl
rm
colorpicker.html
8035
0644
edit
dl
rm
colorsys.html
11919
0644
edit
dl
rm
commands.html
15516
0644
edit
dl
rm
compileall.html
18621
0644
edit
dl
rm
compiler.html
75897
0644
edit
dl
rm
configparser.html
67751
0644
edit
dl
rm
constants.html
13979
0644
edit
dl
rm
contextlib.html
22777
0644
edit
dl
rm
cookie.html
41854
0644
edit
dl
rm
cookielib.html
91032
0644
edit
dl
rm
copy.html
13004
0644
edit
dl
rm
copy_reg.html
14691
0644
edit
dl
rm
crypt.html
10647
0644
edit
dl
rm
crypto.html
7761
0644
edit
dl
rm
csv.html
76456
0644
edit
dl
rm
ctypes.html
264575
0644
edit
dl
rm
curses.ascii.html
24873
0644
edit
dl
rm
curses.html
167501
0644
edit
dl
rm
curses.panel.html
15824
0644
edit
dl
rm
custominterp.html
8026
0644
edit
dl
rm
datatypes.html
18015
0644
edit
dl
rm
datetime.html
253438
0644
edit
dl
rm
dbhash.html
16825
0644
edit
dl
rm
dbm.html
13507
0644
edit
dl
rm
debug.html
10703
0644
edit
dl
rm
decimal.html
222315
0644
edit
dl
rm
development.html
14828
0644
edit
dl
rm
difflib.html
91975
0644
edit
dl
rm
dircache.html
12299
0644
edit
dl
rm
dis.html
84156
0644
edit
dl
rm
distribution.html
7679
0644
edit
dl
rm
distutils.html
10152
0644
edit
dl
rm
dl.html
17668
0644
edit
dl
rm
doctest.html
185883
0644
edit
dl
rm
docxmlrpcserver.html
17573
0644
edit
dl
rm
dumbdbm.html
15549
0644
edit
dl
rm
dummy_thread.html
10065
0644
edit
dl
rm
dummy_threading.html
8934
0644
edit
dl
rm
easydialogs.html
33124
0644
edit
dl
rm
email-examples.html
47424
0644
edit
dl
rm
email.charset.html
29424
0644
edit
dl
rm
email.encoders.html
12847
0644
edit
dl
rm
email.errors.html
17952
0644
edit
dl
rm
email.generator.html
23141
0644
edit
dl
rm
email.header.html
29108
0644
edit
dl
rm
email.html
55722
0644
edit
dl
rm
email.iterators.html
12623
0644
edit
dl
rm
email.message.html
70189
0644
edit
dl
rm
email.mime.html
31655
0644
edit
dl
rm
email.parser.html
35142
0644
edit
dl
rm
email.utils.html
27076
0644
edit
dl
rm
ensurepip.html
18327
0644
edit
dl
rm
errno.html
40246
0644
edit
dl
rm
exceptions.html
63693
0644
edit
dl
rm
fcntl.html
26245
0644
edit
dl
rm
filecmp.html
23997
0644
edit
dl
rm
fileformats.html
9653
0644
edit
dl
rm
fileinput.html
27071
0644
edit
dl
rm
filesys.html
10866
0644
edit
dl
rm
fl.html
56525
0644
edit
dl
rm
fm.html
13009
0644
edit
dl
rm
fnmatch.html
16258
0644
edit
dl
rm
formatter.html
37371
0644
edit
dl
rm
fpectl.html
16879
0644
edit
dl
rm
fpformat.html
11455
0644
edit
dl
rm
fractions.html
24888
0644
edit
dl
rm
framework.html
36934
0644
edit
dl
rm
frameworks.html
7551
0644
edit
dl
rm
ftplib.html
49577
0644
edit
dl
rm
functions.html
205640
0644
edit
dl
rm
functools.html
29645
0644
edit
dl
rm
future_builtins.html
14477
0644
edit
dl
rm
gc.html
28423
0644
edit
dl
rm
gdbm.html
17805
0644
edit
dl
rm
gensuitemodule.html
12574
0644
edit
dl
rm
getopt.html
25280
0644
edit
dl
rm
getpass.html
11426
0644
edit
dl
rm
gettext.html
84971
0644
edit
dl
rm
gl.html
24342
0644
edit
dl
rm
glob.html
14430
0644
edit
dl
rm
grp.html
11316
0644
edit
dl
rm
gzip.html
20576
0644
edit
dl
rm
hashlib.html
25467
0644
edit
dl
rm
heapq.html
34890
0644
edit
dl
rm
hmac.html
14374
0644
edit
dl
rm
hotshot.html
20147
0644
edit
dl
rm
htmllib.html
27682
0644
edit
dl
rm
htmlparser.html
42433
0644
edit
dl
rm
httplib.html
70932
0644
edit
dl
rm
i18n.html
10047
0644
edit
dl
rm
ic.html
18654
0644
edit
dl
rm
idle.html
42148
0644
edit
dl
rm
imageop.html
16099
0644
edit
dl
rm
imaplib.html
58515
0644
edit
dl
rm
imgfile.html
12732
0644
edit
dl
rm
imghdr.html
12238
0644
edit
dl
rm
imp.html
37603
0644
edit
dl
rm
importlib.html
8926
0644
edit
dl
rm
imputil.html
33563
0644
edit
dl
rm
index.html
79088
0644
edit
dl
rm
inspect.html
56823
0644
edit
dl
rm
internet.html
26138
0644
edit
dl
rm
intro.html
9353
0644
edit
dl
rm
io.html
113701
0644
edit
dl
rm
ipc.html
16598
0644
edit
dl
rm
itertools.html
125397
0644
edit
dl
rm
jpeg.html
13757
0644
edit
dl
rm
json.html
73678
0644
edit
dl
rm
keyword.html
8210
0644
edit
dl
rm
language.html
11687
0644
edit
dl
rm
linecache.html
11416
0644
edit
dl
rm
locale.html
61576
0644
edit
dl
rm
logging.config.html
80045
0644
edit
dl
rm
logging.handlers.html
80194
0644
edit
dl
rm
logging.html
110254
0644
edit
dl
rm
mac.html
23376
0644
edit
dl
rm
macos.html
16129
0644
edit
dl
rm
macosa.html
14080
0644
edit
dl
rm
macostools.html
16898
0644
edit
dl
rm
macpath.html
8386
0644
edit
dl
rm
mailbox.html
171121
0644
edit
dl
rm
mailcap.html
14132
0644
edit
dl
rm
markup.html
19862
0644
edit
dl
rm
marshal.html
19456
0644
edit
dl
rm
math.html
44015
0644
edit
dl
rm
md5.html
15123
0644
edit
dl
rm
mhlib.html
24123
0644
edit
dl
rm
mimetools.html
21206
0644
edit
dl
rm
mimetypes.html
30634
0644
edit
dl
rm
mimewriter.html
16078
0644
edit
dl
rm
mimify.html
15279
0644
edit
dl
rm
miniaeframe.html
13109
0644
edit
dl
rm
misc.html
7236
0644
edit
dl
rm
mm.html
9570
0644
edit
dl
rm
mmap.html
30832
0644
edit
dl
rm
modulefinder.html
18096
0644
edit
dl
rm
modules.html
9017
0644
edit
dl
rm
msilib.html
57853
0644
edit
dl
rm
msvcrt.html
21232
0644
edit
dl
rm
multifile.html
26256
0644
edit
dl
rm
multiprocessing.html
414535
0644
edit
dl
rm
mutex.html
12147
0644
edit
dl
rm
netdata.html
18379
0644
edit
dl
rm
netrc.html
14021
0644
edit
dl
rm
new.html
13177
0644
edit
dl
rm
nis.html
11502
0644
edit
dl
rm
nntplib.html
45689
0644
edit
dl
rm
numbers.html
40636
0644
edit
dl
rm
numeric.html
14292
0644
edit
dl
rm
operator.html
93622
0644
edit
dl
rm
optparse.html
250109
0644
edit
dl
rm
os.html
240195
0644
edit
dl
rm
os.path.html
43402
0644
edit
dl
rm
ossaudiodev.html
45594
0644
edit
dl
rm
othergui.html
9403
0644
edit
dl
rm
parser.html
42558
0644
edit
dl
rm
pdb.html
38603
0644
edit
dl
rm
persistence.html
15676
0644
edit
dl
rm
pickle.html
109684
0644
edit
dl
rm
pickletools.html
11475
0644
edit
dl
rm
pipes.html
19685
0644
edit
dl
rm
pkgutil.html
27367
0644
edit
dl
rm
platform.html
31599
0644
edit
dl
rm
plistlib.html
18344
0644
edit
dl
rm
popen2.html
27601
0644
edit
dl
rm
poplib.html
24320
0644
edit
dl
rm
posix.html
16626
0644
edit
dl
rm
posixfile.html
21387
0644
edit
dl
rm
pprint.html
32207
0644
edit
dl
rm
profile.html
72788
0644
edit
dl
rm
pty.html
10195
0644
edit
dl
rm
pwd.html
12388
0644
edit
dl
rm
pyclbr.html
15812
0644
edit
dl
rm
pydoc.html
13650
0644
edit
dl
rm
pyexpat.html
80886
0644
edit
dl
rm
python.html
12854
0644
edit
dl
rm
py_compile.html
11932
0644
edit
dl
rm
queue.html
26856
0644
edit
dl
rm
quopri.html
12739
0644
edit
dl
rm
random.html
42722
0644
edit
dl
rm
re.html
155985
0644
edit
dl
rm
readline.html
37383
0644
edit
dl
rm
repr.html
21778
0644
edit
dl
rm
resource.html
28286
0644
edit
dl
rm
restricted.html
12366
0644
edit
dl
rm
rexec.html
40566
0644
edit
dl
rm
rfc822.html
46408
0644
edit
dl
rm
rlcompleter.html
14460
0644
edit
dl
rm
robotparser.html
13403
0644
edit
dl
rm
runpy.html
21925
0644
edit
dl
rm
sched.html
19878
0644
edit
dl
rm
scrolledtext.html
9728
0644
edit
dl
rm
select.html
44090
0644
edit
dl
rm
sets.html
40151
0644
edit
dl
rm
sgi.html
10371
0644
edit
dl
rm
sgmllib.html
34464
0644
edit
dl
rm
sha.html
13062
0644
edit
dl
rm
shelve.html
29955
0644
edit
dl
rm
shlex.html
35033
0644
edit
dl
rm
shutil.html
45454
0644
edit
dl
rm
signal.html
34023
0644
edit
dl
rm
simplehttpserver.html
20351
0644
edit
dl
rm
simplexmlrpcserver.html
37794
0644
edit
dl
rm
site.html
26887
0644
edit
dl
rm
smtpd.html
13587
0644
edit
dl
rm
smtplib.html
47054
0644
edit
dl
rm
sndhdr.html
10993
0644
edit
dl
rm
socket.html
116414
0644
edit
dl
rm
socketserver.html
76430
0644
edit
dl
rm
someos.html
16472
0644
edit
dl
rm
spwd.html
11163
0644
edit
dl
rm
sqlite3.html
150014
0644
edit
dl
rm
ssl.html
202453
0644
edit
dl
rm
stat.html
34597
0644
edit
dl
rm
statvfs.html
11326
0644
edit
dl
rm
stdtypes.html
298144
0644
edit
dl
rm
string.html
120219
0644
edit
dl
rm
stringio.html
20061
0644
edit
dl
rm
stringprep.html
17729
0644
edit
dl
rm
strings.html
15905
0644
edit
dl
rm
struct.html
44896
0644
edit
dl
rm
subprocess.html
110447
0644
edit
dl
rm
sun.html
7253
0644
edit
dl
rm
sunau.html
30011
0644
edit
dl
rm
sunaudio.html
19236
0644
edit
dl
rm
symbol.html
8140
0644
edit
dl
rm
symtable.html
25871
0644
edit
dl
rm
sys.html
110996
0644
edit
dl
rm
sysconfig.html
26299
0644
edit
dl
rm
syslog.html
19737
0644
edit
dl
rm
tabnanny.html
11393
0644
edit
dl
rm
tarfile.html
88728
0644
edit
dl
rm
telnetlib.html
27782
0644
edit
dl
rm
tempfile.html
31903
0644
edit
dl
rm
termios.html
17309
0644
edit
dl
rm
test.html
57030
0644
edit
dl
rm
textwrap.html
30135
0644
edit
dl
rm
thread.html
21486
0644
edit
dl
rm
threading.html
86655
0644
edit
dl
rm
time.html
63798
0644
edit
dl
rm
timeit.html
40529
0644
edit
dl
rm
tix.html
50582
0644
edit
dl
rm
tk.html
26568
0644
edit
dl
rm
tkinter.html
84316
0644
edit
dl
rm
token.html
20999
0644
edit
dl
rm
tokenize.html
20607
0644
edit
dl
rm
trace.html
28668
0644
edit
dl
rm
traceback.html
40900
0644
edit
dl
rm
ttk.html
108515
0644
edit
dl
rm
tty.html
9753
0644
edit
dl
rm
turtle.html
230483
0644
edit
dl
rm
types.html
29833
0644
edit
dl
rm
undoc.html
24680
0644
edit
dl
rm
unicodedata.html
20186
0644
edit
dl
rm
unittest.html
225021
0644
edit
dl
rm
unix.html
11223
0644
edit
dl
rm
urllib.html
68266
0644
edit
dl
rm
urllib2.html
113380
0644
edit
dl
rm
urlparse.html
43474
0644
edit
dl
rm
user.html
12707
0644
edit
dl
rm
userdict.html
32069
0644
edit
dl
rm
uu.html
11810
0644
edit
dl
rm
uuid.html
30137
0644
edit
dl
rm
warnings.html
50950
0644
edit
dl
rm
wave.html
24894
0644
edit
dl
rm
weakref.html
38808
0644
edit
dl
rm
webbrowser.html
26565
0644
edit
dl
rm
whichdb.html
9499
0644
edit
dl
rm
windows.html
9817
0644
edit
dl
rm
winsound.html
20466
0644
edit
dl
rm
wsgiref.html
88384
0644
edit
dl
rm
xdrlib.html
33018
0644
edit
dl
rm
xml.dom.html
97877
0644
edit
dl
rm
xml.dom.minidom.html
43230
0644
edit
dl
rm
xml.dom.pulldom.html
13835
0644
edit
dl
rm
xml.etree.elementtree.html
111804
0644
edit
dl
rm
xml.html
18007
0644
edit
dl
rm
xml.sax.handler.html
41877
0644
edit
dl
rm
xml.sax.html
23458
0644
edit
dl
rm
xml.sax.reader.html
44802
0644
edit
dl
rm
xml.sax.utils.html
16087
0644
edit
dl
rm
xmlrpclib.html
69191
0644
edit
dl
rm
zipfile.html
62227
0644
edit
dl
rm
zipimport.html
22769
0644
edit
dl
rm
zlib.html
31230
0644
edit
dl
rm
_winreg.html
64631
0644
edit
dl
rm
__builtin__.html
11069
0644
edit
dl
rm
__future__.html
14688
0644
edit
dl
rm
__main__.html
7512
0644
edit
dl
rm
Edit:
/usr/share/doc/python2-docs/html/library/json.html
(73678B)
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>18.2. json — JSON encoder and decoder — Python 2.7.16 documentation</title> <link rel="stylesheet" href="../_static/classic.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.16 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="18.3. mailcap — Mailcap file handling" href="mailcap.html" /> <link rel="prev" title="18.1.11. email: Examples" href="email-examples.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/2/library/json.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="mailcap.html" title="18.3. mailcap — Mailcap file handling" accesskey="N">next</a> |</li> <li class="right" > <a href="email-examples.html" title="18.1.11. email: Examples" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.16 documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="netdata.html" accesskey="U">18. Internet Data Handling</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="module-json"> <span id="json-json-encoder-and-decoder"></span><h1>18.2. <a class="reference internal" href="#module-json" title="json: Encode and decode the JSON format."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code></a> — JSON encoder and decoder<a class="headerlink" href="#module-json" title="Permalink to this headline">¶</a></h1> <div class="versionadded"> <p><span class="versionmodified">New in version 2.6.</span></p> </div> <p><a class="reference external" href="http://json.org">JSON (JavaScript Object Notation)</a>, specified by <span class="target" id="index-0"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc7159.html"><strong>RFC 7159</strong></a> (which obsoletes <span class="target" id="index-1"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc4627.html"><strong>RFC 4627</strong></a>) and by <a class="reference external" href="http://www.ecma-international.org/publications/standards/Ecma-404.htm">ECMA-404</a>, is a lightweight data interchange format inspired by <a class="reference external" href="https://en.wikipedia.org/wiki/JavaScript">JavaScript</a> object literal syntax (although it is not a strict subset of JavaScript <a class="footnote-reference" href="#rfc-errata" id="id1">[1]</a> ).</p> <p><a class="reference internal" href="#module-json" title="json: Encode and decode the JSON format."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code></a> exposes an API familiar to users of the standard library <a class="reference internal" href="marshal.html#module-marshal" title="marshal: Convert Python objects to streams of bytes and back (with different constraints)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">marshal</span></code></a> and <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> modules.</p> <p>Encoding basic Python object hierarchies:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">([</span><span class="s1">'foo'</span><span class="p">,</span> <span class="p">{</span><span class="s1">'bar'</span><span class="p">:</span> <span class="p">(</span><span class="s1">'baz'</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">,</span> <span class="mi">2</span><span class="p">)}])</span> <span class="go">'["foo", {"bar": ["baz", null, 1.0, 2]}]'</span> <span class="gp">>>> </span><span class="nb">print</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="s2">"</span><span class="se">\"</span><span class="s2">foo</span><span class="se">\b</span><span class="s2">ar"</span><span class="p">)</span> <span class="go">"\"foo\bar"</span> <span class="gp">>>> </span><span class="nb">print</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="sa">u</span><span class="s1">'</span><span class="se">\u1234</span><span class="s1">'</span><span class="p">)</span> <span class="go">"\u1234"</span> <span class="gp">>>> </span><span class="nb">print</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="s1">'</span><span class="se">\\</span><span class="s1">'</span><span class="p">)</span> <span class="go">"\\"</span> <span class="gp">>>> </span><span class="nb">print</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">({</span><span class="s2">"c"</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">"b"</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">"a"</span><span class="p">:</span> <span class="mi">0</span><span class="p">},</span> <span class="n">sort_keys</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="go">{"a": 0, "b": 0, "c": 0}</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">StringIO</span> <span class="k">import</span> <span class="n">StringIO</span> <span class="gp">>>> </span><span class="n">io</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">()</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dump</span><span class="p">([</span><span class="s1">'streaming API'</span><span class="p">],</span> <span class="n">io</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">io</span><span class="o">.</span><span class="n">getvalue</span><span class="p">()</span> <span class="go">'["streaming API"]'</span> </pre></div> </div> <p>Compact encoding:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,{</span><span class="s1">'4'</span><span class="p">:</span> <span class="mi">5</span><span class="p">,</span> <span class="s1">'6'</span><span class="p">:</span> <span class="mi">7</span><span class="p">}],</span> <span class="n">separators</span><span class="o">=</span><span class="p">(</span><span class="s1">','</span><span class="p">,</span><span class="s1">':'</span><span class="p">))</span> <span class="go">'[1,2,3,{"4":5,"6":7}]'</span> </pre></div> </div> <p>Pretty printing:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="nb">print</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">({</span><span class="s1">'4'</span><span class="p">:</span> <span class="mi">5</span><span class="p">,</span> <span class="s1">'6'</span><span class="p">:</span> <span class="mi">7</span><span class="p">},</span> <span class="n">sort_keys</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="gp">... </span> <span class="n">indent</span><span class="o">=</span><span class="mi">4</span><span class="p">,</span> <span class="n">separators</span><span class="o">=</span><span class="p">(</span><span class="s1">','</span><span class="p">,</span> <span class="s1">': '</span><span class="p">))</span> <span class="go">{</span> <span class="go"> "4": 5,</span> <span class="go"> "6": 7</span> <span class="go">}</span> </pre></div> </div> <p>Decoding JSON:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'["foo", {"bar":["baz", null, 1.0, 2]}]'</span><span class="p">)</span> <span class="go">[u'foo', {u'bar': [u'baz', None, 1.0, 2]}]</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'"</span><span class="se">\\</span><span class="s1">"foo</span><span class="se">\\</span><span class="s1">bar"'</span><span class="p">)</span> <span class="go">u'"foo\x08ar'</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">StringIO</span> <span class="k">import</span> <span class="n">StringIO</span> <span class="gp">>>> </span><span class="n">io</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">(</span><span class="s1">'["streaming API"]'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">io</span><span class="p">)</span> <span class="go">[u'streaming API']</span> </pre></div> </div> <p>Specializing JSON object decoding:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="k">def</span> <span class="nf">as_complex</span><span class="p">(</span><span class="n">dct</span><span class="p">):</span> <span class="gp">... </span> <span class="k">if</span> <span class="s1">'__complex__'</span> <span class="ow">in</span> <span class="n">dct</span><span class="p">:</span> <span class="gp">... </span> <span class="k">return</span> <span class="nb">complex</span><span class="p">(</span><span class="n">dct</span><span class="p">[</span><span class="s1">'real'</span><span class="p">],</span> <span class="n">dct</span><span class="p">[</span><span class="s1">'imag'</span><span class="p">])</span> <span class="gp">... </span> <span class="k">return</span> <span class="n">dct</span> <span class="gp">...</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'{"__complex__": true, "real": 1, "imag": 2}'</span><span class="p">,</span> <span class="gp">... </span> <span class="n">object_hook</span><span class="o">=</span><span class="n">as_complex</span><span class="p">)</span> <span class="go">(1+2j)</span> <span class="gp">>>> </span><span class="kn">import</span> <span class="nn">decimal</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'1.1'</span><span class="p">,</span> <span class="n">parse_float</span><span class="o">=</span><span class="n">decimal</span><span class="o">.</span><span class="n">Decimal</span><span class="p">)</span> <span class="go">Decimal('1.1')</span> </pre></div> </div> <p>Extending <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a>:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span> <span class="gp">>>> </span><span class="k">class</span> <span class="nc">ComplexEncoder</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">JSONEncoder</span><span class="p">):</span> <span class="gp">... </span> <span class="k">def</span> <span class="nf">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span> <span class="gp">... </span> <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="nb">complex</span><span class="p">):</span> <span class="gp">... </span> <span class="k">return</span> <span class="p">[</span><span class="n">obj</span><span class="o">.</span><span class="n">real</span><span class="p">,</span> <span class="n">obj</span><span class="o">.</span><span class="n">imag</span><span class="p">]</span> <span class="gp">... </span> <span class="c1"># Let the base class default method raise the TypeError</span> <span class="gp">... </span> <span class="k">return</span> <span class="n">json</span><span class="o">.</span><span class="n">JSONEncoder</span><span class="o">.</span><span class="n">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">)</span> <span class="gp">...</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">,</span> <span class="bp">cls</span><span class="o">=</span><span class="n">ComplexEncoder</span><span class="p">)</span> <span class="go">'[2.0, 1.0]'</span> <span class="gp">>>> </span><span class="n">ComplexEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">encode</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">)</span> <span class="go">'[2.0, 1.0]'</span> <span class="gp">>>> </span><span class="nb">list</span><span class="p">(</span><span class="n">ComplexEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">iterencode</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">))</span> <span class="go">['[', '2.0', ', ', '1.0', ']']</span> </pre></div> </div> <p>Using <code class="xref py py-mod docutils literal notranslate"><span class="pre">json.tool</span></code> from the shell to validate and pretty-print:</p> <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>$ echo '{"json":"obj"}' | python -m json.tool { "json": "obj" } $ echo '{1.2:3.4}' | python -mjson.tool Expecting property name enclosed in double quotes: line 1 column 2 (char 1) </pre></div> </div> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">JSON is a subset of <a class="reference external" href="http://yaml.org/">YAML</a> 1.2. The JSON produced by this module’s default settings (in particular, the default <em>separators</em> value) is also a subset of YAML 1.0 and 1.1. This module can thus also be used as a YAML serializer.</p> </div> <div class="section" id="basic-usage"> <h2>18.2.1. Basic Usage<a class="headerlink" href="#basic-usage" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="json.dump"> <code class="descclassname">json.</code><code class="descname">dump</code><span class="sig-paren">(</span><em>obj</em>, <em>fp</em>, <em>skipkeys=False</em>, <em>ensure_ascii=True</em>, <em>check_circular=True</em>, <em>allow_nan=True</em>, <em>cls=None</em>, <em>indent=None</em>, <em>separators=None</em>, <em>encoding="utf-8"</em>, <em>default=None</em>, <em>sort_keys=False</em>, <em>**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#json.dump" title="Permalink to this definition">¶</a></dt> <dd><p>Serialize <em>obj</em> as a JSON formatted stream to <em>fp</em> (a <code class="docutils literal notranslate"><span class="pre">.write()</span></code>-supporting <a class="reference internal" href="../glossary.html#term-file-like-object"><span class="xref std std-term">file-like object</span></a>) using this <a class="reference internal" href="#py-to-json-table"><span class="std std-ref">conversion table</span></a>.</p> <p>If <em>skipkeys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then dict keys that are not of a basic type (<a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>, <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a>, <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a>, <a class="reference internal" href="functions.html#long" title="long"><code class="xref py py-class docutils literal notranslate"><span class="pre">long</span></code></a>, <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>, <a class="reference internal" href="functions.html#bool" title="bool"><code class="xref py py-class docutils literal notranslate"><span class="pre">bool</span></code></a>, <code class="docutils literal notranslate"><span class="pre">None</span></code>) will be skipped instead of raising a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>.</p> <p>If <em>ensure_ascii</em> is true (the default), all non-ASCII characters in the output are escaped with <code class="docutils literal notranslate"><span class="pre">\uXXXX</span></code> sequences, and the result is a <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> instance consisting of ASCII characters only. If <em>ensure_ascii</em> is false, some chunks written to <em>fp</em> may be <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> instances. This usually happens because the input contains unicode strings or the <em>encoding</em> parameter is used. Unless <code class="docutils literal notranslate"><span class="pre">fp.write()</span></code> explicitly understands <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> (as in <a class="reference internal" href="codecs.html#codecs.getwriter" title="codecs.getwriter"><code class="xref py py-func docutils literal notranslate"><span class="pre">codecs.getwriter()</span></code></a>) this is likely to cause an error.</p> <p>If <em>check_circular</em> is false (default: <code class="docutils literal notranslate"><span class="pre">True</span></code>), then the circular reference check for container types will be skipped and a circular reference will result in an <a class="reference internal" href="exceptions.html#exceptions.OverflowError" title="exceptions.OverflowError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OverflowError</span></code></a> (or worse).</p> <p>If <em>allow_nan</em> is false (default: <code class="docutils literal notranslate"><span class="pre">True</span></code>), then it will be a <a class="reference internal" href="exceptions.html#exceptions.ValueError" title="exceptions.ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> to serialize out of range <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a> values (<code class="docutils literal notranslate"><span class="pre">nan</span></code>, <code class="docutils literal notranslate"><span class="pre">inf</span></code>, <code class="docutils literal notranslate"><span class="pre">-inf</span></code>) in strict compliance of the JSON specification. If <em>allow_nan</em> is true, their JavaScript equivalents (<code class="docutils literal notranslate"><span class="pre">NaN</span></code>, <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code>) will be used.</p> <p>If <em>indent</em> is a non-negative integer, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0, or negative, will only insert newlines. <code class="docutils literal notranslate"><span class="pre">None</span></code> (the default) selects the most compact representation.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">Since the default item separator is <code class="docutils literal notranslate"><span class="pre">',</span> <span class="pre">'</span></code>, the output might include trailing whitespace when <em>indent</em> is specified. You can use <code class="docutils literal notranslate"><span class="pre">separators=(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> to avoid this.</p> </div> <p>If specified, <em>separators</em> should be an <code class="docutils literal notranslate"><span class="pre">(item_separator,</span> <span class="pre">key_separator)</span></code> tuple. By default, <code class="docutils literal notranslate"><span class="pre">(',</span> <span class="pre">',</span> <span class="pre">':</span> <span class="pre">')</span></code> are used. To get the most compact JSON representation, you should specify <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':')</span></code> to eliminate whitespace.</p> <p><em>encoding</em> is the character encoding for str instances, default is UTF-8.</p> <p>If specified, <em>default</em> should be a function that gets called for objects that can’t otherwise be serialized. It should return a JSON encodable version of the object or raise a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>. If not specified, <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> is raised.</p> <p>If <em>sort_keys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then the output of dictionaries will be sorted by key.</p> <p>To use a custom <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> subclass (e.g. one that overrides the <code class="xref py py-meth docutils literal notranslate"><span class="pre">default()</span></code> method to serialize additional types), specify it with the <em>cls</em> kwarg; otherwise <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> is used.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">Unlike <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> and <a class="reference internal" href="marshal.html#module-marshal" title="marshal: Convert Python objects to streams of bytes and back (with different constraints)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">marshal</span></code></a>, JSON is not a framed protocol so trying to serialize more objects with repeated calls to <a class="reference internal" href="#json.dump" title="json.dump"><code class="xref py py-func docutils literal notranslate"><span class="pre">dump()</span></code></a> and the same <em>fp</em> will result in an invalid JSON file.</p> </div> </dd></dl> <dl class="function"> <dt id="json.dumps"> <code class="descclassname">json.</code><code class="descname">dumps</code><span class="sig-paren">(</span><em>obj</em>, <em>skipkeys=False</em>, <em>ensure_ascii=True</em>, <em>check_circular=True</em>, <em>allow_nan=True</em>, <em>cls=None</em>, <em>indent=None</em>, <em>separators=None</em>, <em>encoding="utf-8"</em>, <em>default=None</em>, <em>sort_keys=False</em>, <em>**kw</em><span class="sig-paren">)</span><a class="headerlink" href="#json.dumps" title="Permalink to this definition">¶</a></dt> <dd><p>Serialize <em>obj</em> to a JSON formatted <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> using this <a class="reference internal" href="#py-to-json-table"><span class="std std-ref">conversion table</span></a>. If <em>ensure_ascii</em> is false, the result may contain non-ASCII characters and the return value may be a <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> instance.</p> <p>The arguments have the same meaning as in <a class="reference internal" href="#json.dump" title="json.dump"><code class="xref py py-func docutils literal notranslate"><span class="pre">dump()</span></code></a>.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">Keys in key/value pairs of JSON are always of the type <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>. When a dictionary is converted into JSON, all the keys of the dictionary are coerced to strings. As a result of this, if a dictionary is converted into JSON and then back into a dictionary, the dictionary may not equal the original one. That is, <code class="docutils literal notranslate"><span class="pre">loads(dumps(x))</span> <span class="pre">!=</span> <span class="pre">x</span></code> if x has non-string keys.</p> </div> </dd></dl> <dl class="function"> <dt id="json.load"> <code class="descclassname">json.</code><code class="descname">load</code><span class="sig-paren">(</span><em>fp</em><span class="optional">[</span>, <em>encoding</em><span class="optional">[</span>, <em>cls</em><span class="optional">[</span>, <em>object_hook</em><span class="optional">[</span>, <em>parse_float</em><span class="optional">[</span>, <em>parse_int</em><span class="optional">[</span>, <em>parse_constant</em><span class="optional">[</span>, <em>object_pairs_hook</em><span class="optional">[</span>, <em>**kw</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#json.load" title="Permalink to this definition">¶</a></dt> <dd><p>Deserialize <em>fp</em> (a <code class="docutils literal notranslate"><span class="pre">.read()</span></code>-supporting <a class="reference internal" href="../glossary.html#term-file-like-object"><span class="xref std std-term">file-like object</span></a> containing a JSON document) to a Python object using this <a class="reference internal" href="#json-to-py-table"><span class="std std-ref">conversion table</span></a>.</p> <p>If the contents of <em>fp</em> are encoded with an ASCII based encoding other than UTF-8 (e.g. latin-1), then an appropriate <em>encoding</em> name must be specified. Encodings that are not ASCII based (such as UCS-2) are not allowed, and should be wrapped with <code class="docutils literal notranslate"><span class="pre">codecs.getreader(encoding)(fp)</span></code>, or simply decoded to a <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> object and passed to <a class="reference internal" href="#json.loads" title="json.loads"><code class="xref py py-func docutils literal notranslate"><span class="pre">loads()</span></code></a>.</p> <p><em>object_hook</em> is an optional function that will be called with the result of any object literal decoded (a <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>). The return value of <em>object_hook</em> will be used instead of the <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This feature can be used to implement custom decoders (e.g. <a class="reference external" href="http://www.jsonrpc.org">JSON-RPC</a> class hinting).</p> <p><em>object_pairs_hook</em> is an optional function that will be called with the result of any object literal decoded with an ordered list of pairs. The return value of <em>object_pairs_hook</em> will be used instead of the <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This feature can be used to implement custom decoders that rely on the order that the key and value pairs are decoded (for example, <a class="reference internal" href="collections.html#collections.OrderedDict" title="collections.OrderedDict"><code class="xref py py-func docutils literal notranslate"><span class="pre">collections.OrderedDict()</span></code></a> will remember the order of insertion). If <em>object_hook</em> is also defined, the <em>object_pairs_hook</em> takes priority.</p> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 2.7: </span>Added support for <em>object_pairs_hook</em>.</p> </div> <p><em>parse_float</em>, if specified, will be called with the string of every JSON float to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">float(num_str)</span></code>. This can be used to use another datatype or parser for JSON floats (e.g. <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>).</p> <p><em>parse_int</em>, if specified, will be called with the string of every JSON int to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">int(num_str)</span></code>. This can be used to use another datatype or parser for JSON integers (e.g. <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>).</p> <p><em>parse_constant</em>, if specified, will be called with one of the following strings: <code class="docutils literal notranslate"><span class="pre">'-Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'NaN'</span></code>. This can be used to raise an exception if invalid JSON numbers are encountered.</p> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 2.7: </span><em>parse_constant</em> doesn’t get called on ‘null’, ‘true’, ‘false’ anymore.</p> </div> <p>To use a custom <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> subclass, specify it with the <code class="docutils literal notranslate"><span class="pre">cls</span></code> kwarg; otherwise <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> is used. Additional keyword arguments will be passed to the constructor of the class.</p> </dd></dl> <dl class="function"> <dt id="json.loads"> <code class="descclassname">json.</code><code class="descname">loads</code><span class="sig-paren">(</span><em>s</em><span class="optional">[</span>, <em>encoding</em><span class="optional">[</span>, <em>cls</em><span class="optional">[</span>, <em>object_hook</em><span class="optional">[</span>, <em>parse_float</em><span class="optional">[</span>, <em>parse_int</em><span class="optional">[</span>, <em>parse_constant</em><span class="optional">[</span>, <em>object_pairs_hook</em><span class="optional">[</span>, <em>**kw</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#json.loads" title="Permalink to this definition">¶</a></dt> <dd><p>Deserialize <em>s</em> (a <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> or <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> instance containing a JSON document) to a Python object using this <a class="reference internal" href="#json-to-py-table"><span class="std std-ref">conversion table</span></a>.</p> <p>If <em>s</em> is a <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> instance and is encoded with an ASCII based encoding other than UTF-8 (e.g. latin-1), then an appropriate <em>encoding</em> name must be specified. Encodings that are not ASCII based (such as UCS-2) are not allowed and should be decoded to <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> first.</p> <p>The other arguments have the same meaning as in <a class="reference internal" href="#json.load" title="json.load"><code class="xref py py-func docutils literal notranslate"><span class="pre">load()</span></code></a>.</p> </dd></dl> </div> <div class="section" id="encoders-and-decoders"> <h2>18.2.2. Encoders and Decoders<a class="headerlink" href="#encoders-and-decoders" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="json.JSONDecoder"> <em class="property">class </em><code class="descclassname">json.</code><code class="descname">JSONDecoder</code><span class="sig-paren">(</span><span class="optional">[</span><em>encoding</em><span class="optional">[</span>, <em>object_hook</em><span class="optional">[</span>, <em>parse_float</em><span class="optional">[</span>, <em>parse_int</em><span class="optional">[</span>, <em>parse_constant</em><span class="optional">[</span>, <em>strict</em><span class="optional">[</span>, <em>object_pairs_hook</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder" title="Permalink to this definition">¶</a></dt> <dd><p>Simple JSON decoder.</p> <p>Performs the following translations in decoding by default:</p> <table border="1" class="docutils" id="json-to-py-table"> <colgroup> <col width="44%" /> <col width="56%" /> </colgroup> <thead valign="bottom"> <tr class="row-odd"><th class="head">JSON</th> <th class="head">Python</th> </tr> </thead> <tbody valign="top"> <tr class="row-even"><td>object</td> <td>dict</td> </tr> <tr class="row-odd"><td>array</td> <td>list</td> </tr> <tr class="row-even"><td>string</td> <td>unicode</td> </tr> <tr class="row-odd"><td>number (int)</td> <td>int, long</td> </tr> <tr class="row-even"><td>number (real)</td> <td>float</td> </tr> <tr class="row-odd"><td>true</td> <td>True</td> </tr> <tr class="row-even"><td>false</td> <td>False</td> </tr> <tr class="row-odd"><td>null</td> <td>None</td> </tr> </tbody> </table> <p>It also understands <code class="docutils literal notranslate"><span class="pre">NaN</span></code>, <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, and <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code> as their corresponding <code class="docutils literal notranslate"><span class="pre">float</span></code> values, which is outside the JSON spec.</p> <p><em>encoding</em> determines the encoding used to interpret any <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> objects decoded by this instance (UTF-8 by default). It has no effect when decoding <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> objects.</p> <p>Note that currently only encodings that are a superset of ASCII work, strings of other encodings should be passed in as <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a>.</p> <p><em>object_hook</em>, if specified, will be called with the result of every JSON object decoded and its return value will be used in place of the given <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This can be used to provide custom deserializations (e.g. to support JSON-RPC class hinting).</p> <p><em>object_pairs_hook</em>, if specified will be called with the result of every JSON object decoded with an ordered list of pairs. The return value of <em>object_pairs_hook</em> will be used instead of the <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This feature can be used to implement custom decoders that rely on the order that the key and value pairs are decoded (for example, <a class="reference internal" href="collections.html#collections.OrderedDict" title="collections.OrderedDict"><code class="xref py py-func docutils literal notranslate"><span class="pre">collections.OrderedDict()</span></code></a> will remember the order of insertion). If <em>object_hook</em> is also defined, the <em>object_pairs_hook</em> takes priority.</p> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 2.7: </span>Added support for <em>object_pairs_hook</em>.</p> </div> <p><em>parse_float</em>, if specified, will be called with the string of every JSON float to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">float(num_str)</span></code>. This can be used to use another datatype or parser for JSON floats (e.g. <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>).</p> <p><em>parse_int</em>, if specified, will be called with the string of every JSON int to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">int(num_str)</span></code>. This can be used to use another datatype or parser for JSON integers (e.g. <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>).</p> <p><em>parse_constant</em>, if specified, will be called with one of the following strings: <code class="docutils literal notranslate"><span class="pre">'-Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'NaN'</span></code>. This can be used to raise an exception if invalid JSON numbers are encountered.</p> <p>If <em>strict</em> is false (<code class="docutils literal notranslate"><span class="pre">True</span></code> is the default), then control characters will be allowed inside strings. Control characters in this context are those with character codes in the 0–31 range, including <code class="docutils literal notranslate"><span class="pre">'\t'</span></code> (tab), <code class="docutils literal notranslate"><span class="pre">'\n'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\r'</span></code> and <code class="docutils literal notranslate"><span class="pre">'\0'</span></code>.</p> <p>If the data being deserialized is not a valid JSON document, a <a class="reference internal" href="exceptions.html#exceptions.ValueError" title="exceptions.ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> will be raised.</p> <dl class="method"> <dt id="json.JSONDecoder.decode"> <code class="descname">decode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder.decode" title="Permalink to this definition">¶</a></dt> <dd><p>Return the Python representation of <em>s</em> (a <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> or <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> instance containing a JSON document).</p> </dd></dl> <dl class="method"> <dt id="json.JSONDecoder.raw_decode"> <code class="descname">raw_decode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder.raw_decode" title="Permalink to this definition">¶</a></dt> <dd><p>Decode a JSON document from <em>s</em> (a <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> or <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> beginning with a JSON document) and return a 2-tuple of the Python representation and the index in <em>s</em> where the document ended.</p> <p>This can be used to decode a JSON document from a string that may have extraneous data at the end.</p> </dd></dl> </dd></dl> <dl class="class"> <dt id="json.JSONEncoder"> <em class="property">class </em><code class="descclassname">json.</code><code class="descname">JSONEncoder</code><span class="sig-paren">(</span><span class="optional">[</span><em>skipkeys</em><span class="optional">[</span>, <em>ensure_ascii</em><span class="optional">[</span>, <em>check_circular</em><span class="optional">[</span>, <em>allow_nan</em><span class="optional">[</span>, <em>sort_keys</em><span class="optional">[</span>, <em>indent</em><span class="optional">[</span>, <em>separators</em><span class="optional">[</span>, <em>encoding</em><span class="optional">[</span>, <em>default</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder" title="Permalink to this definition">¶</a></dt> <dd><p>Extensible JSON encoder for Python data structures.</p> <p>Supports the following objects and types by default:</p> <table border="1" class="docutils" id="py-to-json-table"> <colgroup> <col width="56%" /> <col width="44%" /> </colgroup> <thead valign="bottom"> <tr class="row-odd"><th class="head">Python</th> <th class="head">JSON</th> </tr> </thead> <tbody valign="top"> <tr class="row-even"><td>dict</td> <td>object</td> </tr> <tr class="row-odd"><td>list, tuple</td> <td>array</td> </tr> <tr class="row-even"><td>str, unicode</td> <td>string</td> </tr> <tr class="row-odd"><td>int, long, float</td> <td>number</td> </tr> <tr class="row-even"><td>True</td> <td>true</td> </tr> <tr class="row-odd"><td>False</td> <td>false</td> </tr> <tr class="row-even"><td>None</td> <td>null</td> </tr> </tbody> </table> <p>To extend this to recognize other objects, subclass and implement a <a class="reference internal" href="#json.JSONEncoder.default" title="json.JSONEncoder.default"><code class="xref py py-meth docutils literal notranslate"><span class="pre">default()</span></code></a> method with another method that returns a serializable object for <code class="docutils literal notranslate"><span class="pre">o</span></code> if possible, otherwise it should call the superclass implementation (to raise <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>).</p> <p>If <em>skipkeys</em> is false (the default), then it is a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> to attempt encoding of keys that are not str, int, long, float or <code class="docutils literal notranslate"><span class="pre">None</span></code>. If <em>skipkeys</em> is true, such items are simply skipped.</p> <p>If <em>ensure_ascii</em> is true (the default), all non-ASCII characters in the output are escaped with <code class="docutils literal notranslate"><span class="pre">\uXXXX</span></code> sequences, and the results are <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> instances consisting of ASCII characters only. If <em>ensure_ascii</em> is false, a result may be a <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> instance. This usually happens if the input contains unicode strings or the <em>encoding</em> parameter is used.</p> <p>If <em>check_circular</em> is true (the default), then lists, dicts, and custom encoded objects will be checked for circular references during encoding to prevent an infinite recursion (which would cause an <a class="reference internal" href="exceptions.html#exceptions.OverflowError" title="exceptions.OverflowError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OverflowError</span></code></a>). Otherwise, no such check takes place.</p> <p>If <em>allow_nan</em> is true (the default), then <code class="docutils literal notranslate"><span class="pre">NaN</span></code>, <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, and <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code> will be encoded as such. This behavior is not JSON specification compliant, but is consistent with most JavaScript based encoders and decoders. Otherwise, it will be a <a class="reference internal" href="exceptions.html#exceptions.ValueError" title="exceptions.ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> to encode such floats.</p> <p>If <em>sort_keys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then the output of dictionaries will be sorted by key; this is useful for regression tests to ensure that JSON serializations can be compared on a day-to-day basis.</p> <p>If <em>indent</em> is a non-negative integer (it is <code class="docutils literal notranslate"><span class="pre">None</span></code> by default), then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. <code class="docutils literal notranslate"><span class="pre">None</span></code> is the most compact representation.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">Since the default item separator is <code class="docutils literal notranslate"><span class="pre">',</span> <span class="pre">'</span></code>, the output might include trailing whitespace when <em>indent</em> is specified. You can use <code class="docutils literal notranslate"><span class="pre">separators=(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> to avoid this.</p> </div> <p>If specified, <em>separators</em> should be an <code class="docutils literal notranslate"><span class="pre">(item_separator,</span> <span class="pre">key_separator)</span></code> tuple. By default, <code class="docutils literal notranslate"><span class="pre">(',</span> <span class="pre">',</span> <span class="pre">':</span> <span class="pre">')</span></code> are used. To get the most compact JSON representation, you should specify <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':')</span></code> to eliminate whitespace.</p> <p>If specified, <em>default</em> should be a function that gets called for objects that can’t otherwise be serialized. It should return a JSON encodable version of the object or raise a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>. If not specified, <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> is raised.</p> <p>If <em>encoding</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>, then all input strings will be transformed into unicode using that encoding prior to JSON-encoding. The default is UTF-8.</p> <dl class="method"> <dt id="json.JSONEncoder.default"> <code class="descname">default</code><span class="sig-paren">(</span><em>o</em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.default" title="Permalink to this definition">¶</a></dt> <dd><p>Implement this method in a subclass such that it returns a serializable object for <em>o</em>, or calls the base implementation (to raise a <a class="reference internal" href="exceptions.html#exceptions.TypeError" title="exceptions.TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>).</p> <p>For example, to support arbitrary iterators, you could implement default like this:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">o</span><span class="p">):</span> <span class="k">try</span><span class="p">:</span> <span class="n">iterable</span> <span class="o">=</span> <span class="nb">iter</span><span class="p">(</span><span class="n">o</span><span class="p">)</span> <span class="k">except</span> <span class="ne">TypeError</span><span class="p">:</span> <span class="k">pass</span> <span class="k">else</span><span class="p">:</span> <span class="k">return</span> <span class="nb">list</span><span class="p">(</span><span class="n">iterable</span><span class="p">)</span> <span class="c1"># Let the base class default method raise the TypeError</span> <span class="k">return</span> <span class="n">JSONEncoder</span><span class="o">.</span><span class="n">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">o</span><span class="p">)</span> </pre></div> </div> </dd></dl> <dl class="method"> <dt id="json.JSONEncoder.encode"> <code class="descname">encode</code><span class="sig-paren">(</span><em>o</em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.encode" title="Permalink to this definition">¶</a></dt> <dd><p>Return a JSON string representation of a Python data structure, <em>o</em>. For example:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">JSONEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">encode</span><span class="p">({</span><span class="s2">"foo"</span><span class="p">:</span> <span class="p">[</span><span class="s2">"bar"</span><span class="p">,</span> <span class="s2">"baz"</span><span class="p">]})</span> <span class="go">'{"foo": ["bar", "baz"]}'</span> </pre></div> </div> </dd></dl> <dl class="method"> <dt id="json.JSONEncoder.iterencode"> <code class="descname">iterencode</code><span class="sig-paren">(</span><em>o</em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.iterencode" title="Permalink to this definition">¶</a></dt> <dd><p>Encode the given object, <em>o</em>, and yield each string representation as available. For example:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">chunk</span> <span class="ow">in</span> <span class="n">JSONEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">iterencode</span><span class="p">(</span><span class="n">bigobject</span><span class="p">):</span> <span class="n">mysocket</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">chunk</span><span class="p">)</span> </pre></div> </div> </dd></dl> </dd></dl> </div> <div class="section" id="standard-compliance-and-interoperability"> <h2>18.2.3. Standard Compliance and Interoperability<a class="headerlink" href="#standard-compliance-and-interoperability" title="Permalink to this headline">¶</a></h2> <p>The JSON format is specified by <span class="target" id="index-2"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc7159.html"><strong>RFC 7159</strong></a> and by <a class="reference external" href="http://www.ecma-international.org/publications/standards/Ecma-404.htm">ECMA-404</a>. This section details this module’s level of compliance with the RFC. For simplicity, <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> and <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> subclasses, and parameters other than those explicitly mentioned, are not considered.</p> <p>This module does not comply with the RFC in a strict fashion, implementing some extensions that are valid JavaScript but not valid JSON. In particular:</p> <ul class="simple"> <li>Infinite and NaN number values are accepted and output;</li> <li>Repeated names within an object are accepted, and only the value of the last name-value pair is used.</li> </ul> <p>Since the RFC permits RFC-compliant parsers to accept input texts that are not RFC-compliant, this module’s deserializer is technically RFC-compliant under default settings.</p> <div class="section" id="character-encodings"> <h3>18.2.3.1. Character Encodings<a class="headerlink" href="#character-encodings" title="Permalink to this headline">¶</a></h3> <p>The RFC requires that JSON be represented using either UTF-8, UTF-16, or UTF-32, with UTF-8 being the recommended default for maximum interoperability. Accordingly, this module uses UTF-8 as the default for its <em>encoding</em> parameter.</p> <p>This module’s deserializer only directly works with ASCII-compatible encodings; UTF-16, UTF-32, and other ASCII-incompatible encodings require the use of workarounds described in the documentation for the deserializer’s <em>encoding</em> parameter.</p> <p>As permitted, though not required, by the RFC, this module’s serializer sets <em>ensure_ascii=True</em> by default, thus escaping the output so that the resulting strings only contain ASCII characters.</p> <p>The RFC prohibits adding a byte order mark (BOM) to the start of a JSON text, and this module’s serializer does not add a BOM to its output. The RFC permits, but does not require, JSON deserializers to ignore an initial BOM in their input. This module’s deserializer raises a <a class="reference internal" href="exceptions.html#exceptions.ValueError" title="exceptions.ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> when an initial BOM is present.</p> <p>The RFC does not explicitly forbid JSON strings which contain byte sequences that don’t correspond to valid Unicode characters (e.g. unpaired UTF-16 surrogates), but it does note that they may cause interoperability problems. By default, this module accepts and outputs (when present in the original <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>) code points for such sequences.</p> </div> <div class="section" id="infinite-and-nan-number-values"> <h3>18.2.3.2. Infinite and NaN Number Values<a class="headerlink" href="#infinite-and-nan-number-values" title="Permalink to this headline">¶</a></h3> <p>The RFC does not permit the representation of infinite or NaN number values. Despite that, by default, this module accepts and outputs <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code>, and <code class="docutils literal notranslate"><span class="pre">NaN</span></code> as if they were valid JSON number literal values:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Neither of these calls raises an exception, but the results are not valid JSON</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="nb">float</span><span class="p">(</span><span class="s1">'-inf'</span><span class="p">))</span> <span class="go">'-Infinity'</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="nb">float</span><span class="p">(</span><span class="s1">'nan'</span><span class="p">))</span> <span class="go">'NaN'</span> <span class="gp">>>> </span><span class="c1"># Same when deserializing</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'-Infinity'</span><span class="p">)</span> <span class="go">-inf</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'NaN'</span><span class="p">)</span> <span class="go">nan</span> </pre></div> </div> <p>In the serializer, the <em>allow_nan</em> parameter can be used to alter this behavior. In the deserializer, the <em>parse_constant</em> parameter can be used to alter this behavior.</p> </div> <div class="section" id="repeated-names-within-an-object"> <h3>18.2.3.3. Repeated Names Within an Object<a class="headerlink" href="#repeated-names-within-an-object" title="Permalink to this headline">¶</a></h3> <p>The RFC specifies that the names within a JSON object should be unique, but does not mandate how repeated names in JSON objects should be handled. By default, this module does not raise an exception; instead, it ignores all but the last name-value pair for a given name:</p> <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">weird_json</span> <span class="o">=</span> <span class="s1">'{"x": 1, "x": 2, "x": 3}'</span> <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="n">weird_json</span><span class="p">)</span> <span class="go">{u'x': 3}</span> </pre></div> </div> <p>The <em>object_pairs_hook</em> parameter can be used to alter this behavior.</p> </div> <div class="section" id="top-level-non-object-non-array-values"> <h3>18.2.3.4. Top-level Non-Object, Non-Array Values<a class="headerlink" href="#top-level-non-object-non-array-values" title="Permalink to this headline">¶</a></h3> <p>The old version of JSON specified by the obsolete <span class="target" id="index-3"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc4627.html"><strong>RFC 4627</strong></a> required that the top-level value of a JSON text must be either a JSON object or array (Python <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a> or <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code>), and could not be a JSON null, boolean, number, or string value. <span class="target" id="index-4"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc7159.html"><strong>RFC 7159</strong></a> removed that restriction, and this module does not and has never implemented that restriction in either its serializer or its deserializer.</p> <p>Regardless, for maximum interoperability, you may wish to voluntarily adhere to the restriction yourself.</p> </div> <div class="section" id="implementation-limitations"> <h3>18.2.3.5. Implementation Limitations<a class="headerlink" href="#implementation-limitations" title="Permalink to this headline">¶</a></h3> <p>Some JSON deserializer implementations may set limits on:</p> <ul class="simple"> <li>the size of accepted JSON texts</li> <li>the maximum level of nesting of JSON objects and arrays</li> <li>the range and precision of JSON numbers</li> <li>the content and maximum length of JSON strings</li> </ul> <p>This module does not impose any such limits beyond those of the relevant Python datatypes themselves or the Python interpreter itself.</p> <p>When serializing to JSON, beware any such limitations in applications that may consume your JSON. In particular, it is common for JSON numbers to be deserialized into IEEE 754 double precision numbers and thus subject to that representation’s range and precision limitations. This is especially relevant when serializing Python <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a> values of extremely large magnitude, or when serializing instances of “exotic” numerical types such as <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>.</p> <p class="rubric">Footnotes</p> <table class="docutils footnote" frame="void" id="rfc-errata" rules="none"> <colgroup><col class="label" /><col /></colgroup> <tbody valign="top"> <tr><td class="label"><a class="fn-backref" href="#id1">[1]</a></td><td>As noted in <a class="reference external" href="https://www.rfc-editor.org/errata_search.php?rfc=7159">the errata for RFC 7159</a>, JSON permits literal U+2028 (LINE SEPARATOR) and U+2029 (PARAGRAPH SEPARATOR) characters in strings, whereas JavaScript (as of ECMAScript Edition 5.1) does not.</td></tr> </tbody> </table> </div> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">18.2. <code class="docutils literal notranslate"><span class="pre">json</span></code> — JSON encoder and decoder</a><ul> <li><a class="reference internal" href="#basic-usage">18.2.1. Basic Usage</a></li> <li><a class="reference internal" href="#encoders-and-decoders">18.2.2. Encoders and Decoders</a></li> <li><a class="reference internal" href="#standard-compliance-and-interoperability">18.2.3. Standard Compliance and Interoperability</a><ul> <li><a class="reference internal" href="#character-encodings">18.2.3.1. Character Encodings</a></li> <li><a class="reference internal" href="#infinite-and-nan-number-values">18.2.3.2. Infinite and NaN Number Values</a></li> <li><a class="reference internal" href="#repeated-names-within-an-object">18.2.3.3. Repeated Names Within an Object</a></li> <li><a class="reference internal" href="#top-level-non-object-non-array-values">18.2.3.4. Top-level Non-Object, Non-Array Values</a></li> <li><a class="reference internal" href="#implementation-limitations">18.2.3.5. Implementation Limitations</a></li> </ul> </li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="email-examples.html" title="previous chapter">18.1.11. <code class="docutils literal notranslate"><span class="pre">email</span></code>: Examples</a></p> <h4>Next topic</h4> <p class="topless"><a href="mailcap.html" title="next chapter">18.3. <code class="docutils literal notranslate"><span class="pre">mailcap</span></code> — Mailcap file handling</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../_sources/library/json.rst.txt" rel="nofollow">Show Source</a></li> </ul> </div> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <div class="searchformwrapper"> <form class="search" action="../search.html" method="get"> <input type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="mailcap.html" title="18.3. mailcap — Mailcap file handling" >next</a> |</li> <li class="right" > <a href="email-examples.html" title="18.1.11. email: Examples" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.16 documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="netdata.html" >18. Internet Data Handling</a> »</li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 1990-2019, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Mar 27, 2019. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>
Save
cmd:
run