problem_25.py

def coding_problem_25(rexp, string):
    """
    Implement regular expression matching with the following special characters:

        . (period) which matches any single character
        * (asterisk) which matches zero or more of the preceding element

    That is, implement a function that takes in a string and a valid regular expression and returns whether or not the
    string matches the regular expression.
    Examples:

    >>> coding_problem_25('ra.', 'ray')
    True
    >>> coding_problem_25('ra.', 'raymond')
    False
    >>> coding_problem_25('.*at', 'chat')
    True
    >>> coding_problem_25('.*at', 'chats')
    False
    """
    pass