An example function for us to write tests for

parse_conn.py

def parse_connection(connection_string):
    """Work out the user name and password in connection_string

    Connection string should be of the form 'database://username@password'
    """
    if '@' in connection_string:
        # Username is characters between '://' and '@'
        slash_position = connection_string.find('://')
        at_position = connection_string.find('@')
        user_name = connection_string[slash_position+3:at_position]
        password = connection_string[at_position+1:]
        return user_name, password

if __name__ == "__main__":
    print parse_connection('mysql://user@pass')
    print parse_connection('a random string')