How to load all modules in a folder?

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')]

Add the __all__ Variable to __init__.py containing:

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

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

Update in 2017: 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.

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

Using importlib the only thing you've got to add is

from importlib import import_module
from pathlib import Path

__all__ = [
    import_module(f".{f.stem}", __package__)
    for f in Path(__file__).parent.glob("*.py")
    if "__" not in f.stem
]
del import_module, Path

When from . import * isn't good enough, this is an improvement over the answer by ted. Specifically, the use of __all__ is not necessary with this approach.

"""Import all modules that exist in the current directory."""
# Ref https://stackoverflow.com/a/60861023/
from importlib import import_module
from pathlib import Path

for f in Path(__file__).parent.glob("*.py"):
    module_name = f.stem
    if (not module_name.startswith("_")) and (module_name not in globals()):
        import_module(f".{module_name}", __package__)
    del f, module_name
del import_module, Path

Note that module_name not in globals() is intended to avoid reimporting the module if it's already imported, as this can risk cyclic imports.

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.

I'd like to add to Anurag Uniyal's answer. You can make it even simpler and get rid of a lot of the imports. Contents of the __init__.py file:

from os import listdir
from os.path import dirname
__all__ = [i[:-3] for i in listdir(dirname(__file__)) if not i.startswith('__') and i.endswith('.py')]

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.

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

I had a nested directory structure i.e. I had multiple directories inside the main directory that contained the python modules.

I added the following script to my __init__.py file to import all the modules

import glob, re, os 

module_parent_directory = "path/to/the/directory/containing/__init__.py/file"

owd = os.getcwd()
if not owd.endswith(module_parent_directory): os.chdir(module_parent_directory)

module_paths = glob.glob("**/*.py", recursive = True)

for module_path in module_paths:
    if not re.match( ".*__init__.py$", module_path):
        import_path = module_path[:-3]
        import_path = import_path.replace("/", ".")
        exec(f"from .{import_path} import *")

os.chdir(owd)

Probably not the best way to achieve this, but I couldn't make anything else work for me.

Here is a solution, with which you do not have to write the file name. Just add this code snippet to your __init__.py

from inspect import isclass
from pkgutil import iter_modules
from pathlib import Path
from importlib import import_module

# iterate through the modules in the current package
package_dir = Path(__file__).resolve().parent
for (_, module_name, _) in iter_modules([package_dir]):

    # import the module and iterate through its attributes
    module = import_module(f"{__name__}.{module_name}")
    for attribute_name in dir(module):
        attribute = getattr(module, attribute_name)

        if isclass(attribute):            
            # Add the class to this package's variables
            globals()[attribute_name] = attribute

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