In Python 3.4+ you can use the pathlib module to get the parent directory.
Example
from pathlib import Path print(Path('/home/username').parent)
Output
This will give the output:
/home
In older versions, you can call the os.path.join on your path and '..'(represents parent directory) and then find its absolute path using os.path.abspath.
Example
import os print(os.path.abspath(os.path.join('/home/username', '..')))
Output
This will give the output:
/home