Python Basics Supplement

One, the file operation

Open () #打开文件

Open (' A.txt ', ' W ', encoding= ' utf-8 ') #防止乱码

R, a, w--read only, append write, write only three modes

u# change the line breaks in all the files to \ n

b# binary operation

The. Read () #读文件

. ReadLine () #读取一行, a row of read files

. ReadLines () #读文件的全部内容, the return is a list

For line in F:

Print (line) #循环读取文件每行内容, recommend this method

The. Write () #写

. Wrielines () #写一个list

. Seek (0) #指定文件指针位置

. Tell () #读文件

. Truncate () #清空

. Close () #关闭文件

. Flush () #缓冲区的文件立即生效

With open (' A.txt ', ' R ') as fw,\ #一行代码写不完可以加一个 \ Connects two lines of code; Use with to write no more. Close

Open (' B.txt ', ' W ', encoding= ' Utf-8 '):

Src_res=fw.read ()

Res=src_res.replace (' xxx ', ' DSSSD ') #替换

Fw.write (res) #如果要修改原文件, you must create a new file and write the modified contents of the original file into the new file.

Os.remove (' A.txt ')

Os.rename (' B.txt ', ' a.txt ') #把原文件删除, rename the new file to the original file

Python Basics Supplement