Python 3ファイル(osライブラリ)でよく使われるシーンと使い方

2020年11月下旬に整理し、平凡に甘んじないあなたにもっとpython 3の基礎知識を捧げます.https://blog.csdn.net/weixin_45316122/article/details/109843899
 
Trick:純demo、心はどこにあるのか、結果はそこにある.
 

import os
"""
1.     
            'a.txt'
1)     
os.rename('abc.txt','a123.txt')
>>'abc.txt'   'a123.txt'
2)    
os.remove('a123.txt')
       ，     'a123.txt'    
  :
if os.path.exists('a123.txt'):
    os.remove('a123.txt')
2.       
         
path='/users/Python/Data/info.txt'
1)    
print os.path.dirname(path)
>>/users/Python/Data
2)     
print os.path.basename(path)
>>info.txt
3)       
print os.path.split(path)
>>('/users/Python/Data', 'info.txt')
3.       
      test01,test02  
1)    
os.mkdir('test01')#          test01  
os.mkdir('test02')#          test02  
  ，                ，     
if not os.path.exists('test01'):
    os.mkdir('test01')
if not os.path.exists('test02'):
    os.mkdir('test02')
2)                
|---test01--------
|---test02--------
|---demo_file.py--
print os.listdir('.')
>>['demo_file.py', 'test01', 'test02']
          test01         ，     ，   
print list(os.walk('.'))#walk()                
>>[('.', ['test01', 'test02'], ['demo_file.py']), ('.\\test01', [], []), ('.\\test02', [], [])]
3)       
print os.getcwd()
>>C:\Users\xx\Python\Test

4)    
os.rmdir('test02')
>>  test02      
     test02           ，   ，      .         shutil   ,

4.           
        ，                         ，               .
python        ,              :
|---test01--------
|---test02--------
|---demo_file.py--

1)       
print os.path.isfile('test01')
>>False
print os.path.isfile('demo_file.py')
>>True

2)       
print os.path.isdir('test01')
>>True

3)       link
 linux      link   
print os.path.islink('link_file')

4)            
                    ，          ,       :
print os.path.exists('demo_file.py')
>>True
print os.path.exists('test01')
>>True
"""

     

# a = {}.fromkeys(("aa","bb","cc"),100)
# # for k,v in a.items():
# #     print(k,v)
#
#
# #      ，   ，          
# # d ={1:'a',2:'b',3:"c"}
# # print(d.get(4,"xx"))
# # print(d.get(3,"xx"))
#
#
# #      
# # aInfo={'Wangdachui':3000,'NiuYun':2000,'LinLing':4500,'Tianqi':8000}
# # template='''
# # Welcome to the pay wall.
# # NiuYun' salary is %(NiuYun)s.
# # Wangdachui's salary is %(Wangdachui)s.
# # '''
# # print(template%aInfo )
#
# #          ，     _  
# # def g():
# #     return 'class room is 203',1000,'2016-10-06'
# # _,price,_=g()
# # print(price)
#
#
# #            ，    None
# # def divide(a,b):
# #    try:
# #       return True,a/b
# #    except ZeroDivisionError:
# #       return False,None
#
# print (divide(0,10))
import time,datetime

#            
# def f(message,when = None):
#     when = datetime.datetime.now()
#     print('%s:%s'%(when,message))
#
# f("hi xiaohonghong")
# time.sleep(1)
# f("hi xiaohonghong again")