Load arbitrary Python files as Modules

load-module-from-arbitrary-file.py

import sys
import os.path

EXT_MODS = dict(
  # module_name => file_path
  cfggen="/usr/local/bin/sonic-cfggen",
  configlet="/usr/bin/configlet"
)

if sys.version_info >= (3, 5):
  from importlib.machinery import SourceFileLoader
  from importlib.util import spec_from_loader, module_from_spec

  for (em_key, em_path) in EXT_MODS.items():
    if not os.path.isfile(em_path):
      raise FileNotFoundError(
        format("Could not find {0} file path {1}.", em_key, em_path))
    spec = spec_from_loader(em_key, SourceFileLoader(em_key, em_path))
    mod = module_from_spec(spec)
    spec.loader.exec_module(mod)
    sys.modules.update({em_key: mod})
  pass

elif sys.version_info >= (2, 7) and sys.version_info < (3, 0):
  import imp
  for (em_key, em_path) in EXT_MODS.items():
    if not os.path.isfile(em_path):
      raise Exception("Could not find {0} file path {1}".format(em_key, em_path))
    mod = imp.load_source(em_key, em_path)
    sys.modules.update({em_key: mod})
  pass

# use module_names as usual
import cfggen
import configlet