python - Import from sibling directory

Question

I have a Python class called "ClassA" and another Python class which is supposed to import ClassA which is "ClassB". The directory structure is as follows:

MainDir
../Dir
..../DirA/ClassA
..../DirB/ClassB

How would I use sys.path so that ClassB can use ClassA?

Answer 1

as a literal answer to the question 'Python Import from parent directory':

to import 'mymodule' that is in the parent directory of your current module:

import os
parentdir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
os.sys.path.insert(0,parentdir) 
import mymodule

edit Unfortunately, the __file__ attribute is not always set. A more secure way to get the parentdir is through the inspect module:

import inspect
currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
parentdir = os.path.dirname(currentdir)