What are the python parameters? Detailed examples of necessary and keyword parameters

In today’s article, we will learn about the parameters in python. The parameters in python are a relatively important and commonly used knowledge point. For example, python3 keyword parameters are used more often in the future. If you search for python keyword on Baidu, it will pop up. So in this article, we will learn about python keyword parameters and python essential parameters.

First we need to know the parameter type, the type is as follows:

Type of parameter:

Required parameters

Key Word parameters

Default parameters

Indefinite length parameters

Required functions

Required parameters must be passed in in the correct order function. The quantity when called must be the same as when declared. When calling the printme() function, you must pass in a parameter, otherwise a syntax error will occur:

#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
#可写函数说明
def printme( str ):
   "打印任何传入的字符串"
   print str;
   return;
 
#调用printme函数
printme();

The output result of the above example:

Traceback (most recent call last):
  File "test.py", line 11, in <module>
    printme();
  TypeError: printme() takes exactly 1 argument (0 given)

Let’s talk about the keyword parameters

Keyword parameters:

Keyword parameters are closely related to function calls. Function calls use keyword parameters to determine the incoming parameter values.

Using keyword arguments allows the function to be called in a different order than when it was declared, because the Python interpreter can match parameter names with parameter values.

The following examples use parameter names when calling function printme():

#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
#可写函数说明
def printme( str ):
   "打印任何传入的字符串"
   print str;
   return;
 
#调用printme函数
printme( str = "My string");

The output results of the above examples:

My string

The following example can show that the order of keyword parameters is not important. More clearly:

#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
#可写函数说明
def printinfo( name, age ):
   "打印任何传入的字符串"
   print "Name: ", name;
   print "Age ", age;
   return;
 
#调用printinfo函数
printinfo( age=50, name="miki" );

The output result of the above example:

Name:  miki
Age  50

The above is what I want to explain today, explaining the classification of parameters and the necessary parameters and key word parameters. Although the above knowledge points give examples, you still need to try it yourself. After all, if you don't do it yourself, it is just like talking on paper. Hands-on practice is the best way and way to verify what you have learned. Finally, I also hope that this article can bring some help to you who are learning python

For more related knowledge, please visit the Python Tutorial column of the php Chinese website.

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