hash unicode string in python

Question

I try to hash some unicode strings:

hashlib.sha1(s).hexdigest()
UnicodeEncodeError: \'ascii\' codec can\'t encode characters in position 0-81: 
ordinal not in ra         


        

Answer 1

Apparently hashlib.sha1 isn't expecting a unicode object, but rather a sequence of bytes in a str object. Encoding your unicode string to a sequence of bytes (using, say, the UTF-8 encoding) should fix it:

>>> import hashlib
>>> s = u'é'
>>> hashlib.sha1(s.encode('utf-8'))

The error is because it is trying to convert the unicode object to a str automatically, using the default ascii encoding, which can't handle all those non-ASCII characters (since your string isn't pure ASCII).

A good starting point for learning more about Unicode and encodings is the Python docs, and this article by Joel Spolsky.