关于python的小总结

1.全局变量global

def function():
    global x
    
    print('x is', x)
    x = 2
    print('Changed local x is', x)

x = 50
function()
print('Value of x is', x)

输出：

root@0f0a1d129745:~/ymy# python py.py
x is 50
Changed local x is 2
Value of x is 2
root@0f0a1d129745:~/ymy#

2.DocString文档字符串

def printMax(x,y):
    ''' Print the maximum of the tow numbers.
    
    The two values must be integers.''' 
    if x > y:
        print(x,'is the maximum')
    else:
        print(y,'is the maximum')

printMax(3,4)

print(printMax.__doc__)

输出：

root@0f0a1d129745:~/ymy# python py.py
4 is the maximum
 Print the maximum of the tow numbers.
    
    The two values must be integers.
root@0f0a1d129745:~/ymy#

3.sys模块

import sys

for i in sys.argv:
    print(i)

print('\n The pythonPath is', sys.path, '\n')

输出：

root@0f0a1d129745:~/ymy# python py.py I love you
py.py
I
love
you

 The pythonPath is ['/root/ymy', '/usr/lib/python36.zip', '/usr/lib/python3.6', '/usr/lib/python3.6/lib-dynload', '/root/.local/lib/python3.6/site-packages', '/usr/local/lib/python3.6/dist-packages', '/usr/lib/python3/dist-packages']

4.__name__

if __name__ == "__main__":
    print('Hello')
else:
    print('World')

输出：

root@0f0a1d129745:~/ymy# python py.py
Hello

root@0f0a1d129745:~/ymy# python
>>> import py
World

5.创建模块

# filename:py.py
def myMoudle():
    print('Hello')

version = '0.1'

# filename:py_demo.py
import py

py.myMoudle()

print('Version',py.version)

输出：

root@0f0a1d129745:~/ymy# python py_demo.py
Hello
Version 0.1
root@0f0a1d129745:~/ymy#

6.dir( ) 函数：列出模块定义的标识符（包括函数、类和变量）

关于python的小总结

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