The hashlib documentation has incorrect examples showing the use of the 
hexdigest() method:

>>> hashlib.sha224(b"Nobody inspects the spammish 
repetition").hexdigest()
b'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'
>>>

and this one

>>> h = hashlib.new('ripemd160')
>>> h.update(b"Nobody inspects the spammish repetition")
>>> h.hexdigest()
b'cc4a5ce1b3df48aec5d22d1f16b894a0b894eccc'
>>>

However, the result of h.hexdigest() is of type 'str', not bytes. Actual 
output:

>>> h.hexdigest()
'cc4a5ce1b3df48aec5d22d1f16b894a0b894eccc'
>>> 

Sure would be nice if that string of hex digits was easy to decode back 
into a binary string.  

>>> import binascii
>>> b = binascii.a2b_hex(h.hexdigest())
>>>

Hmmm. So *SOME* of the functions in binascii do accept Unicode strings. 
See Issue 4470 :-).

Shouldn't hash algorithms give bytes results anyway?

The digest() method of hashes does produce bytes (correct).   The 
hexdigest() method produces a string, but it is also shown as producing 
bytes in the examples.

Fixed in r68027.