Re raising exceptions sandbox

re_raise_exceptions.py

"""
In this example we try to re raise an exception changing its class
"""

import sys


class InputFileNotFoundError(IOError):
    """
    Input file not found
    """
    pass


def read_input_file(input_file):
    """
    Reads the input file

    @param input_file: The input file path
    @type input_file: String

    @return contents: The contents of the file in a string
    @rtype contents: String

    @raises InputFileNotFoundError
    """

    try:
        with open(input_file) as f:
            return f.read()
    except IOError:
        exc_info = sys.exc_info()
        raise InputFileNotFoundError, exc_info[1], exc_info[2]


if __name__ == '__main__':
    input_file = 'this_does_not_exist.txt'
    try:
        read_input_file(input_file)
    except IOError as e:
        exit(1)