File operations
Read the three states file
The first value of mode
r read-only (read-only files)
with open(r"a.txt",mode='r',encoding='utf8') as rf:
w write-only (no it is created, there will be emptied)
with open(r"a.txt",mode='w',encoding='utf8') as wf:
a append (no create, there is appended)
with open(r"a.txt",mode='a',encoding='utf8') as af:
The second value of mode
1 t text represented in text mode write mode (default mode t) (must not be used alone and in combination rwa)
with open(r"a.txt",mode='rt',encoding='utf8') as rtf:
2 b binary pattern represented in binary write mode (as binary mode without encoding attribute)
(Must not be used alone and in combination rwa)
with open(r'a.exe',mode='rb') as rbf:
Copies of documents
A copy of a movie
import os
with open(r'C:\Users\wu_oldBoy\Desktop\JoJo31.mp4',
mode='rb') as readmovie, \ #因为电影不是文本文件 所以用'rb'读取,写也是用'wb'
open(r"C:\Users\wu_oldBoy\Desktop\JoJo31copy.mp4",mode="wb") as newmovie:
for i in readmovie:
newmovie.write(i) #测试md5值一致,拷贝成功
#替换掉原有文件 (虽然只是复制了文件)
os.remove('C:\Users\wu_oldBoy\Desktop\JoJo31.mp4')
os.rename('C:\Users\wu_oldBoy\Desktop\JoJo31copy.mp4','C:\Users\wu_oldBoy\Desktop\JoJo31.mp4')