This can be used to decode a JSON document from a string that may have

extraneous data at the end.

..versionchanged::3.14

Now ignores any leading whitespace instead of returning an error

..class::JSONEncoder(*, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False, indent=None, separators=None, default=None)

obj,end=self.raw_decode(s,idx=_w(s,0).end())

obj,end=self.raw_decode(s)

end=_w(s,end).end()

ifend!=len(s):

raiseJSONDecodeError("Extra data",s,end)

defraw_decode(self,s,idx=0):

defraw_decode(self,s,idx=0,_w=WHITESPACE.match):

try:

obj,end=self.scan_once(s,idx)

obj,end=self.scan_once(s,idx=_w(s,idx).end())

exceptStopIterationaserr:

raiseJSONDecodeError("Expecting value",s,err.value)fromNone

returnobj,end

withself.assertRaises(ValueError):

self.loads('1'* (maxdigits+1))

classTestRawDecode:

deftest_whitespace(self):

decoder=self.json.JSONDecoder()

self.assertEqual(decoder.raw_decode(' {}'), ({},3))

self.assertEqual(decoder.raw_decode(' []'), ([],4))

self.assertEqual(decoder.raw_decode(' ""'), ('',5))

s=' { "key" : "value" , "k":"v" }\n' \

val1,n1=decoder.raw_decode(s)

val2,n2=decoder.raw_decode(s[n1:])

self.assertEqual(val1, {"key":"value","k":"v"})

self.assertEqual(val2, {"key":"value","k":"v"})

classTestPyDecode(TestDecode,PyTest):pass

classTestCDecode(TestDecode,CTest):pass

classTestPyRawDecode(TestRawDecode,PyTest):pass

classTestCRawDecode(TestRawDecode,CTest):pass

Ignore leading whitespace in:func:`JSONDecoder.raw_decode`