How to read bits from a file?

Question

I know how to read bytes — x.read(number_of_bytes), but how can I read bits in Python?

I have to read only 5 bits (not 8 bits [1 byte]) from a binary fi

Answer 1

Python can only read a byte at a time. You'd need to read in a full byte, then just extract the value you want from that byte, e.g.

b = x.read(1)
firstfivebits = b >> 3

Or if you wanted the 5 least significant bits, rather than the 5 most significant bits:

b = x.read(1)
lastfivebits = b & 0b11111

Some other useful bit manipulation info can be found here: http://wiki.python.org/moin/BitManipulation