Python file operations

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I. File reading and writing

Examples are as follows:

1 #!/usr/bin/env python2 #-*-coding:utf-8-*-3 " "4 Read the file5 " "6 defread_file (filename):7     #Open the file as read-only, the file must exist, or throw an exception8F=open (filename,'R')9     #Read File contentsTenContent =F.read () One     Printcontent A     #Close File - f.close () -  the " " - Write a file - " " - defwrite_file (filename): +     #Open the file as written, and the file does not exist, re-create -f = open (filename,'W') +     #Write Content AF.write ('Hello World!!! \ n') at     #Close File - f.close () -  - if  __name__=="__main__": -Read_file ('./a.txt') -Write_file ('./b.txt')

Some of the modes for Open are as follows:

W is opened in writing, the file does not exist, it is created with overwrite write operation a in append mode (starting with EOF, creating a new file if necessary) r+ read-write mode open W+ read-write mode open (see W) a+ read-write mode Open (see a) RB Open WB in binary read mode opens in binary write mode (see W) AB opens in binary append mode (see a) RB+ opens in binary reading mode (see r+ ) WB+ opens in binary read/write mode (see w+< c8>) AB+ opens in binary read/write mode (see A +)

Some functions and methods of file operation

Name	Role	Note
Read (n)	Read files by bytes (bytes)	N Optional, do not fill the default read all
ReadLine ()	Read a row	Reads again before closing, and then reads the next line
ReadLines ()	Read all Rows	Returns the result as a list
Write (obj)	Writing objects to a file	General Write As String
Writelines (seq)	Write a tuple to a file	No newline writes, only data in tuples is written to
Close ()	Close File	An exception will be thrown when the file is closed
Flush ()	Writes buffer data to the hard disk	Data can be written to a file before the close file
Fileno ()	Returns the file label for a long integer type
Tell ()	Returns the location of the file's current operation, with the origin of the file header
Seek (Offest)	Move the file action tag to the specified offest location	Files that are opened in a a+,a manner, each time a write operation is marked Move to the end of the file and seek cannot take effect
Next ()	Move a file action tag to the next line
Turncate (N)	Intercepts a file to a specified size	Write permission required

　　

Python file operations