A detailed explanation of the definition of Python function variable parameter and its parameter transfer method

This article gives an example of the python function variable parameter definition and its parameter passing method. Share to everyone for your reference. The specific analysis is as follows:

The function indeterminate parameters in Python are defined in the following form:

1, func (*args)

The arguments passed in are args in a tuple form, such as:

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def func (*args): Print args >>> func (1,2,3) (1, 2, 3) >>> func (*[1,2,3)) #这个方式可以直接将一个列表的所有元素当作不定参数 incoming (1, 2, 3)

2, func (**kwargs)

The arguments passed in are args in the form of a dictionary, such as:

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def func (**kwargs): Print Kwargs >>> func (a = 1,b = 2, c = 3) {' A ': 1, ' C ': 3, ' B ': 2} >>> func (**{' a ': 1 , ' B ': 2, ' C ': 3} ' #这个方式可以直接将一个字典的所有键值对当作关键字参数传入 {' A ': 1, ' C ': 3, ' B ': 2}

3, can also be mixed with the two

Func (*args, **kwargs)

The order of incoming must be the same as the order of definition, here is an indefinite argument list, and then a dictionary of keyword parameters, such as:

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def func (*args, **kwargs): Print args print Kwargs >>> func (1,2,3) (1, 2, 3) {} >>> func (*[1,2,3)) (1, 2 , 3) {} >>> func (a = 1, b = 2, c = 3) () {' A ': 1, ' C ': 3, ' B ': 2} >>> func (**{' a ': 1, ' B ': 2, ' C ': 3} ') () { ' A ': 1, ' C ': 3, ' B ': 2} >>> func (1,2,3, a = 4, b=5, c=6) (1, 2, 3) {' A ': 4, ' C ': 6, ' B ': 5}</span> #这样跳跃传递是 No. >>> func (1,2,3, a=4, b=5, c=6, 7) syntaxerror:non-keyword arg after keyword arg

I hope this article will help you with your Python programming.