python 基础之第十天

Posted 2020-10-03

局部变量与全局变量

局部变量：在函数里面定义的，只有当函数活动时才生效

全局变量：不在函数里面的

In [1]: x=10

In [2]: def bar():
   ...:     x=20
   ...:     print x
   ...:     

In [3]: x
Out[3]: 10

#####如果一定要改变全局的变量，使用global参数####
In [5]: def bar():
   ...:     global x
   ...:     x = 20

In [6]: x
Out[6]: 10

In [7]: bar()

In [8]: x
Out[8]: 20

########################################################################

有个需求：x,y 的和，x一直都是10，每次调用都要输入10，很麻烦，用add10 = partial(add,10)  就只需要输入一次

from functools import partial

def add(x,y):
    return x+y

if __name__ == ‘__main__‘:
     print add(10,20)
     print add(10,40)
     print add(10,89)
     add10 = partial(add,10)
     print add10(50)

结果：

[[email protected] script]# python add10.py
30
50
99
60

################列出所有目录下的文件#############

[[email protected] script]# vim lsdir.py          
#!/usr/bin/python
# coding:utf-8


import sys
import os



def lsdir(folder):
    contents = os.listdir(folder)
    print ‘\033[31;1m%s\033[0m:\n\033[32;1m%s\033[0m\n‘ % (folder,contents)
    for item in contents:
        full_path = os.path.join(folder,item)
        if os.path.isdir(full_path):
            lsdir(full_path)


if __name__ == ‘__main__‘:
    lsdir(sys.argv[1])

效果：

[[email protected] script]# python lsdir.py /home/
/home/:
[‘herry‘, ‘honey‘, ‘11111.txt‘, ‘hosts‘, ‘fush‘, ‘jerry‘, ‘mima‘, ‘demo‘, ‘cesh.txt‘, ‘fush.txt‘, ‘master‘]

/home/herry:
[‘.bashrc‘, ‘.bash_logout‘, ‘.bash_profile‘]

/home/honey:
[‘.bashrc‘, ‘.bash_logout‘, ‘.bash_profile‘]

/home/fush:
[‘.bashrc‘, ‘.bash_logout‘, ‘.bash_profile‘]

/home/jerry:
[‘.bashrc‘, ‘.bash_logout‘, ‘.bash_profile‘]

############lsdir2.py#################

[[email protected] script]# vim lsdir2.py          
#!/usr/bin/python


import os
import sys


def lsdir(folder):
    for path,dirs,files in os.walk(folder):
        print ‘%s:\n%s\n‘ % (path,(dirs+files))



if __name__ == ‘__main__‘:
    lsdir(sys.argv[1])