how to deserialize a python printed dictionary?

Question

I have python's str dictionary representations in a database as varchars, and I want to retrieve the original python dictionaries

How to have a dictionary again, based in the str representation of a dictionay?

Example

>>> dic = {u'key-a':u'val-a', "key-b":"val-b"}
>>> dicstr = str(dic)
>>> dicstr
"{'key-b': 'val-b', u'key-a': u'val-a'}"

In the example would be turning dicstr back into a usable python dictionary.

Answer 1

Use ast.literal_eval() and for such cases prefer repr() over str(), as str() doesn't guarantee that the string can be converted back to useful object.

In [7]: import ast

In [10]: dic = {u'key-a':u'val-a', "key-b":"val-b"}

In [11]: strs = repr(dic)

In [12]: strs
Out[12]: "{'key-b': 'val-b', u'key-a': u'val-a'}"

In [13]: ast.literal_eval(strs)
Out[13]: {u'key-a': u'val-a', 'key-b': 'val-b'}

Answer 2

You can use eval() or ast.literal_eval(). Most repr() strings can be evaluated back into the original object:

>>> import ast
>>> ast.literal_eval("{'key-b': 'val-b', u'key-a': u'val-a'}")
{'key-b': 'val-b', u'key-a': u'val-a'}