How to load all modules in a folder?

Question

Could someone provide me with a good way of importing a whole directory of modules?
I have a structure like this:

/Foo
    bar.py
    spam.py
    eggs.py

I tried just converting it to a package by adding __init__.py and doing from Foo import * but it didn't work the way I had hoped.

Answer 1

List all python (.py) files in the current folder and put them as __all__ variable in __init__.py

from os.path import dirname, basename, isfile, join
import glob
modules = glob.glob(join(dirname(__file__), "*.py"))
__all__ = [ basename(f)[:-3] for f in modules if isfile(f) and not f.endswith('__init__.py')]

Answer 2

Add the __all__ Variable to __init__.py containing:

__all__ = ["bar", "spam", "eggs"]

See also http://docs.python.org/tutorial/modules.html

Answer 3

Update: Today you probably want to use importlib instead.

Make the Foo directory a package by adding an __init__.py. In that __init__.py add:

import bar
import eggs
import spam

Since you want it dynamic (which may or may not be a good idea), list all py-files with list dir and import them with something like this:

import os
for module in os.listdir(os.path.dirname(__file__)):
    if module == '__init__.py' or module[-3:] != '.py':
        continue
    __import__(module[:-3], locals(), globals())
del module

Then, from your code do this:

import Foo

You can now access the modules with

Foo.bar
Foo.eggs
Foo.spam

etc. from Foo import * is not a good idea for several reasons, including name clashes and making it hard to analyze the code.

Answer 4

Expanding on Mihail's answer, I believe the non-hackish way (as in, not handling the file paths directly) is the following:

1. create an empty __init__.py file under Foo/
2. Execute

import pkgutil
import sys


def load_all_modules_from_dir(dirname):
    for importer, package_name, _ in pkgutil.iter_modules([dirname]):
        full_package_name = '%s.%s' % (dirname, package_name)
        if full_package_name not in sys.modules:
            module = importer.find_module(package_name
                        ).load_module(full_package_name)
            print module


load_all_modules_from_dir('Foo')

You'll get:

<module 'Foo.bar' from '/home/.../Foo/bar.pyc'>
<module 'Foo.spam' from '/home/.../Foo/spam.pyc'>

Answer 5

Python, include all files under a directory:

For newbies who just can't get it to work who need their hands held.

1. Make a folder /home/el/foo and make a file main.py under /home/el/foo Put this code in there:

   from hellokitty import *
   spam.spamfunc()
   ham.hamfunc()
   

2. Make a directory /home/el/foo/hellokitty

3. Make a file __init__.py under /home/el/foo/hellokitty and put this code in there:

   __all__ = ["spam", "ham"]
   

4. Make two python files: spam.py and ham.py under /home/el/foo/hellokitty

5. Define a function inside spam.py:

   def spamfunc():
     print "Spammity spam"
   

6. Define a function inside ham.py:

   def hamfunc():
     print "Upgrade from baloney"
   

7. Run it:

   el@apollo:/home/el/foo$ python main.py 
   spammity spam
   Upgrade from baloney
   

Answer 6

I got tired of this problem myself, so I wrote a package called automodinit to fix it. You can get it from http://pypi.python.org/pypi/automodinit/.

Usage is like this:

1. Include the automodinit package into your setup.py dependencies.
2. Replace all __init__.py files like this:

__all__ = ["I will get rewritten"]
# Don't modify the line above, or this line!
import automodinit
automodinit.automodinit(__name__, __file__, globals())
del automodinit
# Anything else you want can go after here, it won't get modified.

That's it! From now on importing a module will set __all__ to a list of .py[co] files in the module and will also import each of those files as though you had typed:

for x in __all__: import x

Therefore the effect of "from M import *" matches exactly "import M".

automodinit is happy running from inside ZIP archives and is therefore ZIP safe.

Niall

Answer 7

I know I'm updating a quite old post, and I tried using automodinit, but found out it's setup process is broken for python3. So, based on Luca's answer, I came up with a simpler answer - which might not work with .zip - to this issue, so I figured I should share it here:

within the __init__.py module from yourpackage:

#!/usr/bin/env python
import os, pkgutil
__all__ = list(module for _, module, _ in pkgutil.iter_modules([os.path.dirname(__file__)]))

and within another package below yourpackage:

from yourpackage import *

Then you'll have all the modules that are placed within the package loaded, and if you write a new module, it'll be automagically imported as well. Of course, use that kind of things with care, with great powers comes great responsibilities.

Answer 8

import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)
for imp, module, ispackage in pkgutil.walk_packages(path=__path__, prefix=__name__+'.'):
  __import__(module)

Answer 9

I have also encountered this problem and this was my solution:

import os

def loadImports(path):
    files = os.listdir(path)
    imps = []

    for i in range(len(files)):
        name = files[i].split('.')
        if len(name) > 1:
            if name[1] == 'py' and name[0] != '__init__':
               name = name[0]
               imps.append(name)

    file = open(path+'__init__.py','w')

    toWrite = '__all__ = '+str(imps)

    file.write(toWrite)
    file.close()

This function creates a file (in the provided folder) named __init__.py, which contains an __all__ variable that holds every module in the folder.

For example, I have a folder named Test which contains:

Foo.py
Bar.py

So in the script I want the modules to be imported into I will write:

loadImports('Test/')
from Test import *

This will import everything from Test and the __init__.py file in Test will now contain:

__all__ = ['Foo','Bar']

Answer 10

Anurag's example with a couple of corrections:

import os, glob

modules = glob.glob(os.path.join(os.path.dirname(__file__), "*.py"))
__all__ = [os.path.basename(f)[:-3] for f in modules if not f.endswith("__init__.py")]

Answer 11

Anurag Uniyal answer with suggested improvements!

#!/usr/bin/python
# -*- encoding: utf-8 -*-

import os
import glob

all_list = list()
for f in glob.glob(os.path.dirname(__file__)+"/*.py"):
    if os.path.isfile(f) and not os.path.basename(f).startswith('_'):
        all_list.append(os.path.basename(f)[:-3])

__all__ = all_list  

Answer 12

See that your __init__.py defines __all__. The modules - packages doc says

The __init__.py files are required to make Python treat the directories as containing packages; this is done to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path. In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable, described later.

...

The only solution is for the package author to provide an explicit index of the package. The import statement uses the following convention: if a package’s __init__.py code defines a list named __all__, it is taken to be the list of module names that should be imported when from package import * is encountered. It is up to the package author to keep this list up-to-date when a new version of the package is released. Package authors may also decide not to support it, if they don’t see a use for importing * from their package. For example, the file sounds/effects/__init__.py could contain the following code:

__all__ = ["echo", "surround", "reverse"]

This would mean that from sound.effects import * would import the three named submodules of the sound package.

Answer 13

This is the best way i've found so far:

from os.path import dirname, join, isdir, abspath, basename
from glob import glob
pwd = dirname(__file__)
for x in glob(join(pwd, '*.py')):
    if not x.startswith('__'):
        __import__(basename(x)[:-3], globals(), locals())

Answer 14

Look at the pkgutil module from the standard library. It will let you do exactly what you want as long as you have an __init__.py file in the directory. The __init__.py file can be empty.

Answer 15

I've created a module for that, which doesn't rely on __init__.py (or any other auxiliary file) and makes me type only the following two lines:

import importdir
importdir.do("Foo", globals())

Feel free to re-use or contribute: http://gitlab.com/aurelien-lourot/importdir

Answer 16

Just import them by importlib and add them to __all__ (add action is optional) in recurse in the __init__.py of package.

/Foo
    bar.py
    spam.py
    eggs.py
    __init__.py

# __init__.py
import os
import importlib
pyfile_extes = ['py', ]
__all__ = [importlib.import_module('.%s' % filename, __package__) for filename in [os.path.splitext(i)[0] for i in os.listdir(os.path.dirname(__file__)) if os.path.splitext(i)[1] in pyfile_extes] if not filename.startswith('__')]
del os, importlib, pyfile_extes