Add an attribute to pathlib.Path testing if a file/directory/symlink is executable or the user has executable permissions.

I've been trying to find a pythonic way for this (preferably in pathlib.Path) but all I found was trips to the shell and back.

This issue proposes adding an attribute (which I haven't figured the name most would like but it would be somewhere near .can_execute or .is_exe)

As a new feature, this could only go into 3.10, 3.9 is in feature freeze.

The requirements are unclear, it could mean any of:

- the file's *owner* has the execute bit set;

- the file's mode has any execute bit set;

- the *current user* has execute permission (regardless of whether they are the file owner, part of the file's group, or other);

- the file is an executable file (an app or exe) rather than a script that calls an executable file;

- the file is *not* on a file system that has disabled execution;

- if the file is double-clicked in a graphical shell, the file will run as a script or program (as opposed to merely open for reading);

etc.

So the concept of "is this file executable?" is more complex than it seems.

But you could start with getting the execute bit for the file's owner:


import pathlib
import stat
p = pathlib.Path('some file')
p.stat().st_mode & stat.S_IXUSR


or you could try this to find out whether the file *may* be executable for the current user:


os.access(p, os.X_OK)



but read the docs for some complications:

https://docs.python.org/3/library/os.html#os.access

Since pathlib.Path has module os synonyms, I think it would be reasonable to test with os.X_OK. Correct me if I'm wrong.

I think most people would want to check if the current user running the script could execute something.

Also, an App (at least on MacOS) is technically an executable (I've ran iMessage from the command line before).

Now I think of it, it would be weird to just add attributes testing for executable permissions. Why not add the attributes from os.access to pathlib.Path?

 - Path.can_execute = os.access(path, os.X_OK)
 - Path.can_read    = os.access(path, R_OK) 
...

Ok, so I just made a patch implementing this using os.access. It adds the following methods to pathlib.Path

 - can_read    = Returns True if the user can read the path
 - can_write   = Returns True if the user can write on the path
 - can_execute = Returns True if the user can execute the path

These are implemented via

 - return os.access(str(self), os.R_OK)
 - return os.access(str(self), os.W_OK)
 - return os.access(str(self), os.X_OK)

respectively.