Single versus double quotes in json loads in Python

I notice that single quotes cause simplejson's loads function to fail:

>>> import simplejson as json
>>> json.loads("\"foo\"")
'foo'
>>> json.loads("\'foo\'")
Traceback (most recent call last):
...
ValueError: No JSON object could be decoded

I'm parsing things like: foo = ["a", "b", "c"] from a textfile into lists in Python and would like to also accept foo = ['a', 'b', 'c']. simplejson is convenient for making foo automatically into a list.

How can I get loads to accept single quotes, or automatically substitute double for single quotes without wrecking the input? thanks.