Proper way to use **kwargs in Python

python keyword-argument
Kekoa picture Kekoa · Jul 8, 2009 · Viewed 412.4k times · Source

What is the proper way to use **kwargs in Python when it comes to default values?

kwargs returns a dictionary, but what is the best way to set default values, or is there one? Should I just access it as a dictionary? Use get function? 

class ExampleClass:
    def __init__(self, **kwargs):
        self.val = kwargs['val']
        self.val2 = kwargs.get('val2')

A simple question, but one that I can't find good resources on. People do it different ways in code that I've seen and it's hard to know what to use.

Answer

balpha picture balpha · Jul 8, 2009

You can pass a default value to get() for keys that are not in the dictionary:

self.val2 = kwargs.get('val2',"default value")

However, if you plan on using a particular argument with a particular default value, why not use named arguments in the first place?

def __init__(self, val2="default value", **kwargs):

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