Computing an md5 hash of a data structure

Question

I want to compute an md5 hash not of a string, but of an entire data structure. I understand the mechanics of a way to do this (dispatch on the type of the value, canonical

Answer 1

You could use the builtin pprint that will cover some more cases than the proposed json.dumps() solution. For example datetime-objects will be handled correctly.

Your example rewritten to use pprint instead of json:

>>> import hashlib, random, pprint
>>> for i in range(10):
...     k = [i*i for i in range(1000)]
...     random.shuffle(k)
...     d = dict.fromkeys(k, 1)
...     print hashlib.md5(pprint.pformat(d)).hexdigest()
... 
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db
b4e5de6e1c4f3c6540e962fd5b1891db