Question

I am getting a JSON string which has a "\r" character somewhere e.g. "{"data":"foo \r\n bar"}" when I try to parse it throws ValueError.

>>> j="""{"data":"foo \r\n bar"}"""
>>> import json
>>> f=json.loads(j)

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    f=json.loads(j)
  File "C:\Python27\lib\json\__init__.py", line 326, in loads
    return _default_decoder.decode(s)
  File "C:\Python27\lib\json\decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\Python27\lib\json\decoder.py", line 382, in raw_decode
    obj, end = self.scan_once(s, idx)
ValueError: Invalid control character at: line 1 column 13 (char 13)
>>> j[13]
'\r'

"\r" is a perfectly legal character in a Python string.

How can I parse this JSON string, such that

>>> dct = somehow_parse_json(j)
>>> dct['data']
'foo \r\n bar'

I could easily just find and pop carriage return characters, but I would prefer if they can be saved.

Answer 1

You should escape slashes in JSON:

j="""{"data":"foo \\r\\n bar"}"""

If you are not escaping them, your JSON is invalid (being valid Python string).