So for this I am trying to change only the group permissions for a file using chmod. I was able to add a executable permission to the group using
permissions = os.stat(filepath)
os.chmod(filepath, permissions.st_mode | stat.S_IXGRP)
I added the execute permission to the group successfully using this code but I don't know how to remove the permission if needed. Can anyone help me with this.
You don't remove a permission. You set a new permission. So you can set the permission to read or read+write; those variants don't have executable permission.
If you AND (&) the current permission with a combined read + write permission, it should effectively remove the execute permission. So,
os.chmod(filepath, permissions.st_mmode & (stat.IRGRP | stat.IWGRP)
Only the common modes will remain in the second argument, and any execute permission will be removed.
Disclaimer: I haven't checked nor used this, but if it's all bitmasks, this should work.