python __import__ from same folder fails

Question

I have a directory structure like so:

|- project
 |- commands.py
 |- Modules
 | |- __init__.py
 | |- base.py
 | \- build.py
 \- etc....

I have the following code in __init__.py

commands = []
hooks = []
def load_modules():
 """ dynamically loads commands from the /modules subdirectory """
 path = "\\".join(os.path.abspath(__file__).split("\\")[:-1])
 modules = [f for f in os.listdir(path) if f.endswith(".py") and f != "__init__.py"]
 print modules
 for file in modules:
 try:
 module = __import__(file.split(".")[0])
 print module
 for obj_name in dir(module):
 try:
 potential_class = getattr(module, obj_name)
 if isinstance(potential_class, Command):
 #init command instance and place in list
 commands.append(potential_class(serverprops))
 if isinstance(potential_class, Hook):
 hooks.append(potential_class(serverprops))
 except:
 pass
 except ImportError as e:
 print "!! Could not load %s: %s" % (file, e)
 print commands
 print hooks

I'm trying to get __init__.py to load the appropriate commands and hooks into the lists given, however i always hit an ImportError at module = __import__(file.split(".")[0]) even though __init__.py and base.py etc are all in the same folder. i have verified that nothing in any of the module files requires anything in __init__.py, so i'm really at a loss of what to do.

• Chris Morgan: __import__ has quite a few fiddly bits you need to be aware of, especially to do with fromlist. Try searching for that and see if you can figure it out.
• Chris Morgan: path = os.path.dirname(os.path.abspath(__file__)) (more correct and incidentally cross-platform)
• martineau: From where and how is load_modules() invoked?
• Thomas: load_modules is invoked from commands.py during init

Answer 1

All you're missing is having Modules on the system path. Add

import sys
sys.path.append(path)

after your path = ... line and you should be set. Here's my test script:

import os, os.path, sys
print '\n'.join(sys.path) + '\n' * 3
commands = []
hooks = []
def load_modules():
 """ dynamically loads commands from the /modules subdirectory """
 path = os.path.dirname(os.path.abspath(__file__))
 print "In path:", path in sys.path
 sys.path.append(path)
 modules = [f for f in os.listdir(path) if f.endswith(".py") and f != "__init__.py"]
 print modules
 for file in modules:
 try:
 modname = file.split(".")[0]
 module = __import__(modname)
 for obj_name in dir(module):
 print '%s.%s' % (modname, obj_name )
 except ImportError as e:
 print "!! Could not load %s: %s" % (file, e)
 print commands
load_modules()