注意你的__init__.py定义了__all__。模块-包文档说

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.

2017年更新:你可能想用importlib代替。

通过添加__init__.py使Foo目录成为一个包。在__init__.py中添加:

import bar
import eggs
import spam

因为你希望它是动态的(这可能是也可能不是一个好主意)，用list dir列出所有的py-files，然后像这样导入它们:

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

然后，从你的代码这样做:

import Foo

您现在可以使用

Foo.bar
Foo.eggs
Foo.spam

从Foo导入*不是一个好主意，有几个原因，包括名称冲突，使其难以分析代码。

只需通过importlib导入它们，并在包的__init__.py中递归地将它们添加到__all__(添加操作是可选的)。

/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

我想补充Anurag Uniyal的回答。 你可以让它变得更简单，去掉大量的导入。 __init__.py文件的内容:

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')]

这里有一个解决方案，您不必写文件名。只需将此代码片段添加到__init__.py中

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

源

列出当前文件夹中的所有python (.py)文件，并将它们作为__init__.py中的__all__变量

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')]