使用json.dumps()时出现UnicodeDecodeError错误

Question

我有以下字符串在我的Python列表中（来自命令提示符）：

>>> o['records'][5790]
(5790, 'Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ', 60,
 True, '40141613')
>>>

我已经尝试了这里提到的建议：更改Python的默认编码？ 进一步将默认编码更改为utf-16。但是仍然会出现以下异常：json.dumps()。

>>> write(o)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "okapi_create_master.py", line 49, in write
    o = json.dumps(output)
  File "C:\Python27\lib\json\__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "C:\Python27\lib\json\encoder.py", line 201, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "C:\Python27\lib\json\encoder.py", line 264, in iterencode
    return _iterencode(o, 0)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xe1 in position 25: invalid
continuation byte

我无法确定这些字符串需要哪种转换方式才能使json.dumps()正常工作。

- deostroll

---

参见：https://dev59.com/u2Ml5IYBdhLWcg3wgnSl - dreftymac

Answer 1

\xe1无法使用utf-8、utf-16编码进行解码。

>>> '\xe1'.decode('utf-8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\encodings\utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xe1 in position 0: unexpected end of data
>>> '\xe1'.decode('utf-16')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\encodings\utf_16.py", line 16, in decode
    return codecs.utf_16_decode(input, errors, True)
UnicodeDecodeError: 'utf16' codec can't decode byte 0xe1 in position 0: truncated data

尝试使用latin-1编码：

>>> record = (5790, 'Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ',
...           60, True, '40141613')
>>> json.dumps(record, encoding='latin1')
'[5790, "Vlv-Gate-Assy-Mdl-\\u00e1M1-2-\\u00e19/16-10K-BB Credit Memo            ", 60, true, "40141613"]'

或者，指定ensure_ascii=False，json.dumps来使json.dumps不尝试解码字符串。

>>> json.dumps(record, ensure_ascii=False)
'[5790, "Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ", 60, true, "40141613"]'

- falsetru

---

使用ensure_ascii=False是最快速的去除错误的方法。 - coanor

Answer 2

我曾遇到类似的问题，并想出以下方法来确保从任何输入中获得Unicode或字节字符串。简而言之，包含并使用以下lambda函数：

# guarantee unicode string
_u = lambda t: t.decode('UTF-8', 'replace') if isinstance(t, str) else t
_uu = lambda *tt: tuple(_u(t) for t in tt) 
# guarantee byte string in UTF8 encoding
_u8 = lambda t: t.encode('UTF-8', 'replace') if isinstance(t, unicode) else t
_uu8 = lambda *tt: tuple(_u8(t) for t in tt)

应用于您的问题：

import json
o = (5790, u"Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ", 60,
 True, '40141613')
as_json = json.dumps(_uu8(*o))
as_obj = json.loads(as_json)
print "object\n ", o
print "json (type %s)\n %s " % (type(as_json), as_json)
print "object again\n ", as_obj

=>

object
  (5790, u'Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ', 60, True, '40141613')
json (type <type 'str'>)
  [5790, "Vlv-Gate-Assy-Mdl-\u00e1M1-2-\u00e19/16-10K-BB Credit Memo            ", 60, true, "40141613"]
object again
  [5790, u'Vlv-Gate-Assy-Mdl-\xe1M1-2-\xe19/16-10K-BB Credit Memo            ', 60, True, u'40141613']

以下是一些关于此的更多解释。

- miraculixx