os.access() - os

The method access() uses the real uid/gid to test for access to path.
Most operations will use the effective uid/gid, therefore this routine can be used in a suid/sgid environment to test if the invoking user has the specified access to path.
It returns True if access is allowed, False if not.
Parameters : 
path -- This is the path which would be tested for existence or any access.
mode -- This should be F_OK to test the existence of path, or it can be the inclusive OR of one or more of R_OK, W_OK, and X_OK to test permissions.
os.F_OK: Value to pass as the mode parameter of access() to test the existence of path.
os.R_OK: Value to include in the mode parameter of access() to test the readability of path.
os.W_OK Value to include in the mode parameter of access() to test the writability of path.
os.X_OK Value to include in the mode parameter of access() to determine if path can be executed.

Syntax

os.access(path, mode);

Example

#!/usr/bin/python

import os, sys

# Assuming /tmp/foo.txt exists and has read/write permissions.

ret = os.access("/tmp/foo.txt", os.F_OK)
print "F_OK - return value %s"% ret

ret = os.access("/tmp/foo.txt", os.R_OK)
print "R_OK - return value %s"% ret

ret = os.access("/tmp/foo.txt", os.W_OK)
print "W_OK - return value %s"% ret

ret = os.access("/tmp/foo.txt", os.X_OK)
print "X_OK - return value %s"% ret

Output / Return Value

This method returns True if access is allowed, False if not.
FOR Above Example : 
F_OK - return value True
R_OK - return value True
W_OK - return value True
X_OK - return value False

Limitations

Alternatives / See Also

Reference