default_args.py

def kwargs_default(params):
    """Decorator for setting default keyword parameters

    @kwargs_default((('number_of_chickens', 3),))
    will add param 'number_of_chickens' with value of 3 into kwargs.

    :param params: tuple of tuples consiting of name of parameter and value
    :type params: tuple of tuples with str and any ((str, any), (str, any), ...)

    """
    def decorate(func):
        def wrapped(*args, **kwargs):
            for name, value in params:
                if name not in kwargs:
                    kwargs[name] = value
            return func(*args, **kwargs)
        return wrapped
    return decorate