Python os.open() Method
Python OS File/Directory Methods
Overview
The os.open() method is used to open a file and set the required opening options. The mode parameter is optional and defaults to 0777.
Syntax
open()The method syntax is as follows:
os.open(file, flags[, mode]);
Parameters
file-- The file to open
flags-- This parameter can be the following options, separated by "|" when multiple are used:
- os.O_RDONLY:Open in read-only mode
- os.O_WRONLY:Open in write-only mode
- os.O_RDWR :Open in read-write mode
- os.O_NONBLOCK:Open without blocking
- os.O_APPEND:Open in append mode
- os.O_CREAT:Create and open a new file
- os.O_TRUNC:Open a file and truncate its length to zero (must have write permission)
- os.O_EXCL:Return an error if the specified file exists
- os.O_SHLOCK:Automatically acquire a shared lock
- os.O_EXLOCK:Automatically acquire an exclusive lock
- os.O_DIRECT:Eliminate or reduce cache effects
- os.O_FSYNC :Synchronous write
- os.O_NOFOLLOW:Do not follow symbolic links
mode-- Similar tochmod()。
Return Value
Returns the file descriptor of the newly opened file.
Example
The following example demonstrates the use of the open() method:
#!/usr/bin/python # -*- coding: UTF-8 -*- import os, sys # 打开文件 fd = os.open( "foo.txt", os.O_RDWR|os.O_CREAT ) # 写入字符串 os.write(fd, "This is test") # 关闭文件 os.close( fd ) print "关闭文件成功!!"
The output of the above program is:
File closed successfully!!Other Extensions