<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def parser(input_file_path='config.json'):
    '''
    Parser for the .json file containing the configuration of the method.
    '''

    # --- Read .json file
    try:
        with open(input_file_path, 'r') as config_file:
            config_new = json.load(config_file)
            config_file.close()
    except:
        raise Exception('Config file "'+input_file_path+'" not loaded properly. Please check it an try again.')

    import copy
    options = update_config(config_new, copy.deepcopy(default_config))

    return options