python's json parsing function does not support single quoted strings

Using the json parsing function json.loads of the python standard library cannot use single quotes to quote the json string. The example is as follows:

Use double quotes instead, or call json.dumps(a) before loads.

>>> a = "{'aa':'dd','dd':'df'}"
>>> import json
>>> b = json.loads(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.6/json/__init__.py", line 307, in loads
    return _default_decoder.decode(s)
  File "/usr/lib64/python2.6/json/decoder.py", line 319, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib64/python2.6/json/decoder.py", line 336, in raw_decode
    obj, end = self._scanner.iterscan(s, **kw).next()
  File "/usr/lib64/python2.6/json/scanner.py", line 55, in iterscan
    rval, next_pos = action(m, context)
  File "/usr/lib64/python2.6/json/decoder.py", line 171, in JSONObject
    raise ValueError(errmsg("Expecting property name", s, end))
ValueError: Expecting property name: line 1 column 1 (char 1)
>>> a = &#39;{"aa":"asdf","dd":"dfads"}
  File "<stdin>", line 1
    a = &#39;{"aa":"asdf","dd":"dfads"}
                                  ^
SyntaxError: EOL while scanning string literal
>>> a = &#39;{"aa":"asdf","dd":"dfads"}&#39;
>>> b = json.loads(a)
>>> b
>>> <span style="font-family: Helvetica, Tahoma, Arial, sans-serif; line-height: 1.5; background-color: white;">{u&#39;aa&#39;: u&#39;asdf&#39;, u&#39;dd&#39;: u&#39;dfads&#39;}</span><span style="font-family: Helvetica, Tahoma, Arial, sans-serif; line-height: 1.5; background-color: white;">
</span>