Python Unicode Ascii, Ordinal not In range, frustrating error

Question

Here is my problem...

Database stores everything in unicode. hashlib.sha256().digest() accepts str and returns str.

When I try to stuff hash function with the data, I get the famous error:

UnicodeDecodeError: 'ascii' codec can't decode byte 0x90 in position 1: ordinal not in range(128)

This is my data

>>> db_digest
u"'\x90\x017~1\xe0\xaf4\xf2\xec\xd5]:j\xef\xe6\x80\x88\x89\xfe\xf7\x99,c\xff\xb7\x06hXR\x99\xad\x91\x93lM:\xafT\xc9j\xec\xc3\xb7\xea[\x80\xe0e\xd6\\\xd8\x16'\xcb6\xc8\xaa\xdf\xc9 :\xff"
>>> 
>>> hashlib.sha256(db_digest)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\x90' in position 1: ordinal not in range(128)
>>> 
>>> asc_db_digest
"'\x90\x017~1\xe0\xaf4\xf2\xec\xd5]:j\xef\xe6\x80\x88\x89\xfe\xf7\x99,c\xff\xb7\x06hXR\x99\xad\x91\x93lM:\xafT\xc9j\xec\xc3\xb7\xea[\x80\xe0e\xd6\\\xd8\x16'\xcb6\xc8\xaa\xdf\xc9 :\xff"
>>> hashlib.sha256(asc_db_digest)
<sha256 HASH object @ 0x7f7da0f04300>

So all I am asking for is a way to turn db_digest into asc_db_digest

Edit I have rephrased the question as it seems I haven't recognized teh problem correctly at first place.

Answer 1

If you have a unicode string that only contains code points from 0 to 255 (bytes) you can convert it to a Python str using the raw_unicode_escape encoding:

>>> db_digest = u"'\x90\x017~1\xe0\xaf4\xf2\xec\xd5]:j\xef\xe6\x80\x88\x89\xfe\xf7\x99,c\xff\xb7\x06hXR\x99\xad\x91\x93lM:\xafT\xc9j\xec\xc3\xb7\xea[\x80\xe0e\xd6\\\xd8\x16'\xcb6\xc8\xaa\xdf\xc9 :\xff"
>>> hash_digest = "'\x90\x017~1\xe0\xaf4\xf2\xec\xd5]:j\xef\xe6\x80\x88\x89\xfe\xf7\x99,c\xff\xb7\x06hXR\x99\xad\x91\x93lM:\xafT\xc9j\xec\xc3\xb7\xea[\x80\xe0e\xd6\\\xd8\x16'\xcb6\xc8\xaa\xdf\xc9 :\xff"
>>> db_digest.encode('raw_unicode_escape')
"'\x90\x017~1\xe0\xaf4\xf2\xec\xd5]:j\xef\xe6\x80\x88\x89\xfe\xf7\x99,c\xff\xb7\x06hXR\x99\xad\x91\x93lM:\xafT\xc9j\xec\xc3\xb7\xea[\x80\xe0e\xd6\\\xd8\x16'\xcb6\xc8\xaa\xdf\xc9 :\xff"
>>> db_digest.encode('raw_unicode_escape') == hash_digest
True