(python) meaning of st_mode

It's the permission bits of the file.

>>> oct(16877)
'040755'

See the various stat.S_* attributes for more info.

The standard stat module can help you interpret these values from os.stat:

The stat module defines constants and functions for interpreting the results of os.stat(), os.fstat() and os.lstat() (if they exist). For complete details about the stat(), fstat() and lstat() calls, consult the documentation for your system.