What's the best way to implement "from . import *" in Python?

Question

I'm using Django, and I like to separate my models, views, and tests into subdirectories.

But, this means that I need to maintain an __init__.py in each subdirectory that imports every module in that directory.

I'd rather just put some call in that says:

from some_library import import_everything
import_everything()

That would have the same effect as iterating over the current directory and importing every .py file in that directory.

What's the best/easiest way to implement this?

Here are what my django application directories (essentially) look like:

some_django_app/
    models/
        __init__.py
        create.py
        read.py
        update.py 
        delete.py
    views/
        __init__.py
        create.py
        read.py
        update.py
        delete.py
    forms/ 
        __init__.py
        create.py
        update.py
    tests/
        __init__.py
        create.py
        read.py
        update.py
        delete.py

So, you can see that to make a "proper" Django app, all my init.py files need to import all the other .py files in each directory. I'd rather just have some simple boilerplate there.

Note that `from . import *` is generally a bad idea because namespaces can be overwritten without your knowledge. See the [documentation on the subject](http://docs.python.org/howto/doanddont.html#from-module-import) — Joel Cornett, Jan 30 '12 at 19:42
Worth a read, mind you: http://stackoverflow.com/questions/3615125/should-wildcard-import-be-avoided — Steve Jalim, Jan 30 '12 at 19:56

Izkata · Answer 1 · 2012-01-30T19:17:37.510

4

Within your app/models/__init__.py add these lines:

    from app.models.create import *
    from app.models.read import *
    from app.models.update import *
    from app.models.delete import *

This'll be your best bet for conciseness and readability. from app.models import * will now load all classes/etc from within each of the other files. Likewise, from app.models import foo will load foo no matter which of these files it's defined in.

edited Jan 30 '12 at 19:17

answered Jan 30 '12 at 19:12

Izkata

8,961
2
40
50

Yes, that's exactly what I'm doing now and I find it burdensome. For every new test case or form, I need to keep updating __init__.py. For most cases (models, views) this is OK but for tests it's the worst, since I like to have lots of files there instead of one giant tests.py and __init__.py is getting dozens of lines in it. – slacy Jan 30 '12 at 20:10
@slacy That sounds like a bad way to organize it. Why not split your tests into logical groupings - model_tests.py, view_tests.py, and so on? (Or some other grouping that makes sense for that app, like user_tests, guest_tests, or whatever) – Izkata Jan 30 '12 at 21:04
Yeah, actually, we do have model_tests.py and view_tests, but even those files get >1000 lines and we end up splitting them out. :) – slacy Jan 30 '12 at 22:28

score 1 · Answer 2 · edited May 23 '17 at 12:11

Using the information given in synthesizerpatel's answer, you could implement import_everything this way:

import os
import sys

def import_everything(path):
    # Insert near the beginning so path will be the item removed with sys.path.remove(path) below
    # (The case when sys.path[0] == path works fine too).
    # Do not insert at index 0 since sys.path[0] may have a special meaning
    sys.path.insert(1,path)
    for filename in os.listdir(path):
        if filename.endswith('.py'):
            modname = filename.replace('.py', '')
            module = __import__(modname, fromlist = [True])
            attrs = getattr(module, '__all__',
                            (attr for attr in dir(module) if not attr.startswith('_')))
            for attr in attrs:
                # print('Adding {a}'.format(a = attr))
                globals()[attr] = getattr(module, attr)
    sys.path.remove(path)

and could be used like this:

print(globals().keys())
# ['import_everything', '__builtins__', '__file__', '__package__', 'sys', '__name__', 'os', '__doc__']

import_everything(os.path.expanduser('~/test'))

print(globals().keys())
# ['hashlib', 'pythonrc', 'import_everything', '__builtins__', 'get_input', '__file__', '__package__', 'sys', 'mp', 'time', 'home', '__name__', 'main', 'os', '__doc__', 'user']

What's the best way to implement "from . import *" in Python?

2 Answers2