ChecksumChecker.py | MD5 Checksum of a file in Python

#! /usr/bin/env python
# ChecksumChecker.py
# Author: Abdul Fatir
# E-Mail: abdulfatirs@gmail.com

from threading import Thread
import hashlib
import optparse

def getChecksum(file_path,check_hash):
    file_handle = open(file_path,"rb")
    _md5 = hashlib.md5()
    while True:
        _buffer = file_handle.read()
        if not _buffer:
            break
        _md5.update(_buffer)
    digest = _md5.hexdigest()
    print "[+] File's MD5 checksum is: "+digest
    if (check_hash != None):
        if(check_hash.lower() == digest):
            print "[+] Hash matched: The file is authentic."
        else:
            print "[-] Hash mis-match: The file is not authentic."

def Main():
    parser = optparse.OptionParser('usage: %prog -f <filename> [-m <md5 hash>]')
    parser.add_option('-f', dest='file_path', type='string', help='Please specify a file')
    parser.add_option('-m', dest='check_hash', type='string')
    (options,arg) = parser.parse_args()
    if (options.file_path == None):
        print parser.usage
        exit(0)
    else:
        file_path = options.file_path
        check_hash = options.check_hash
    print "[*] Hashing file '"+ file_path +"'...."
    hash_thread = Thread(target=getChecksum,args=(file_path,check_hash))
    hash_thread.start()
    hash_thread.join()
if __name__  == '__main__':
    Main()