python add module from another directory

import sys
# sys.path is a list of absolute path strings
sys.path.append('/path/to/application/app/folder')

import file

# test.py
import sys
# append current python modules' folder path
# example: need to import module.py present in '/path/to/python/module/not/in/syspath'
sys.path.append('/path/to/python/module/not/in/syspath')

import module

# some_file.py
import sys
# insert at 1, 0 is the script path (or '' in REPL)
sys.path.insert(1, '/path/to/application/app/folder')

import file