Named arguments: C# vs Python

Both C# and Python allow named arguments, s开发者_StackOverflow中文版o you can write something like: foo(bar:1). This is great, especially in combination with optional arguments.

My question is: what are the differences between the C# and Python named arguments, if any? I'm not interested in which is the "best", but in whether there are differences and in the possible motivations behind these differences.

And if someone knows of differences with other languages' implementations of this feature (Ruby or Objective-C, maybe), that could be interesting too.

edited to make community-wiki

Python lets you "catch" unspecified named arguments into a dict, which is pretty handy

>>> def f(**kw):
...     print kw
... 
>>> f(size=3, sides=6, name="hexagon")
{'sides': 6, 'name': 'hexagon', 'size': 3}

Python not only lets you catch unspecified named arguments into a dict, but also lets you unpack a dict into arguments:

    >>> def f(alfa, beta, gamma):
    ...     print alfa, beta, gamma
    ...
    >>> f(**{'alfa': 1, 'beta': 2, 'gamma': 3})
    1 2 3

and pass them down the stream:

    >>> def g(**kwargs):
    ...     f(**kwargs)
    ...
    >>> g(**{'alfa': 1, 'beta': 2, 'gamma': 3})
    1 2 3