compute crc of file in python

Question

I want to calculate the CRC of file and get output like: E45A12AC. Here's my code:

#!/usr/bin/env python  import os, sys import zlib  def crc(fileName):     fd = open(fileName,"rb")     content = fd.readlines()     fd.close()     for eachLine in content:         zlib.crc32(eachLine)  for eachFile in sys.argv[1:]:     crc(eachFile) 

This calculates the CRC for each line, but its output (e.g. -1767935985) is not what I want.

Hashlib works the way I want, but it computes the md5:

import hashlib m = hashlib.md5() for line in open('data.txt', 'rb'):     m.update(line) print m.hexdigest() 

Is it possible to get something similar using zlib.crc32?

Answer 1

A little more compact and optimized code

def crc(fileName):     prev = 0     for eachLine in open(fileName,"rb"):         prev = zlib.crc32(eachLine, prev)     return "%X"%(prev & 0xFFFFFFFF) 

PS2: Old PS is deprecated - therefore deleted -, because of the suggestion in the comment. Thank you. I don't get, how I missed this, but it was really good.