[Tutor] the "**" operator?

[Piotr Kamiński]

Dnia 10-12-2010 o 20:14:30 Alex Hall <mehgcap at gmail.com> napisał(a):

> Hi all,
> I was googling a way to do something like
> mydict=mydict.extend(additionaldict)
>
> and someone on a forum recommends this:
> mydict=dict(mydict, **additionaldict)
> What is the ** doing here?


As far as I know the ** indicates that the argument passed (here named:  
additionaldict) is a dictionary. One * would mean that it is a tuple.

I'm not sure but it seams to me that the usual way to *update* a  
dictionary with the contents of an other dictionary is to use the .update  
dictionary method.

Examples:

>>> animals= {'cat': 'Bobo', 'dog': 'Rex'}
>>> animals2= {'cow': 'some name that I can\'t think of right now',  
>>> 'bird': 'Falco'}
>>> animals.update(animals2)
>>> print animals
{'bird': 'Falco', 'dog': 'Rex', 'cow': "some name that I can't think of  
right now", 'cat': 'Bobo'}
>>> print animals2
{'bird': 'Falco', 'cow': "some name that I can't think of right now"}
>>>

Hope my answers are right and it helps,

Piotr