Pro Python File Handling!

file_open.py

import logging


def count_lines(filename):
    """
    Count the number of lines in a file. If the file can't be opened it should be treated as an empty file
    :param filename:
    """
    f = None
    try:
        f = open(filename, 'r')
        lines = f.readlines()
    except TypeError as e:
        # invalid file
        logging.error(e)
        return 0
    except EnvironmentError as e:
        # error reading file
        logging.error(e.args[1])
        return 0
    except UnicodeDecodeError as e:
        # contents of file in unknown encoding
        logging.error(e)
        return 0
    else:
        return len(lines)
    finally:
        if f:
            f.close()