Code source de ensae_teaching_cs.homeblog.utils_file

"""
Reasonably inefficient functions about files.


:githublink:`%|py|5`
"""
import hashlib


def checksum_md5(filename):
    """
    computes MD5 for a file

    :param      filename:        filename
    :return:                     string or None if there was an error


    :githublink:`%|py|12`
    """
    fname = filename
    block_size = 0x10000

    fd = open(fname, "rb")
    try:
        block = [fd.read(block_size)]
        while len(block[-1]) > 0:
            block.append(fd.read(block_size))
        contents = block
        zero = hashlib.md5()
        i = 0
        for el in contents:
            i += 1
            zero.update(el)
        m = zero
        return m.hexdigest()
    finally:
        fd.close()
    return None