How to Read Bytes from a file

[gregpinero at gmail.com]

It seems like this would be easy but I'm drawing a blank.

What I want to do is be able to open any file in binary mode, and read
in one byte (8 bits) at a time and then count the number of 1 bits in
that byte.

I got as far as this but it is giving me strings and I'm not sure how
to accurately get to the byte/bit level.

f1=file('somefile','rb')
while 1:
    abyte=f1.read(1)

Thanks in advance for any help.

-Greg