This article describes the universal parameters python function of mass participation Detailed, paper sample code described in great detail, has a certain reference value of learning for all of us to learn or work, a friend in need can refer to
us through a simple example to show how universal function parameters, let's write a simple function
def test(*args,**kwargs):
print(args,kwargs)
Then define two variables
l = [1,2,3,4]
d = {"a":1,"b":2}
Below we look at two kinds of mass participation in any different way
The first way
est(l,d)
If the transfer mode using the above parameters, the l, d 2 variables which are passed to the args parameter, as the two elements of the args variable, kwargs an empty dictionary, he does not pass any parameters a
([1, 2, 3, 4], {'a': 1, 'b': 2}) {}
We can see a list of dictionary d and l are treated as two of the elements of a tuple
The second way
test(*l,**d)
If the above way of mass participation, then l will be assigned to the variable args, d will be assigned to the variable kwargs
(1, 2, 3, 4) {'a': 1, 'b': 2}
by the above presentation, you should basically understand the universal parameters of a python, it would not know if the function uses universal parameters, how you should pass a reference to
Today was confused, again comb the universal parameters
Look at this function
def foo(action=None,**kwargs):
print("action",action,sep="=================>")
print("kwargs", kwargs, sep="=================>")
d = {"a":1,"b":2}
foo(d)
print("=".center(100,"*"))
foo(**d)
Finally, I performed as follows
Let me explain
The first way to call the function, passing into a dictionary, the dictionary will be passed as a whole into account, the dictionary will be assigned to the position has changed, that is, action
The second function is called method, passing through into the dictionary method **, so he actually passed a = 1, b = 2 this pass go, in fact, a variable name, and the name of these two variables are not the results of action, so the second way is to call
action to none
kwargs is a dictionary
A third method we call in view
d = {"action":"action","a":1}
foo(**d)
The following look at the results, whether you understand some of the
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