Python method open() opens the file file and set various flags according to flags and possibly its mode according to mode.The default mode is 0777 (octal), and the current umask value is first masked out.
Following is the syntax for open() method −
os.open(file, flags[, mode]);
file − File name to be opened.
flags − The following constants are options for the flags. They can be combined using the bitwise OR operator |. Some of them are not available on all platforms.
os.O_RDONLY − open for reading only
os.O_WRONLY − open for writing only
os.O_RDWR − open for reading and writing
os.O_NONBLOCK − do not block on open
os.O_APPEND − append on each write
os.O_CREAT − create file if it does not exist
os.O_TRUNC − truncate size to 0
os.O_EXCL − error if create and file exists
os.O_SHLOCK − atomically obtain a shared lock
os.O_EXLOCK − atomically obtain an exclusive lock
os.O_DIRECT − eliminate or reduce cache effects
os.O_FSYNC − synchronous writes
os.O_NOFOLLOW − do not follow symlinks
mode − This work in similar way as it works for chmod() method.
This method returns the file descriptor for the newly opened file.
The following example shows the usage of open() method.
#!/usr/bin/python import os, sys # Open a file fd = os.open( "foo.txt", os.O_RDWR|os.O_CREAT ) # Write one string os.write(fd, "This is test") # Close opened file os.close( fd ) print "Closed the file successfully!!"
This would create given file foo.txt and then would write given content in that file and would produce following result −
Closed the file successfully!!