The role of the __init__.py file in the Python module package

package1/__init__.py module1.py module2.py package2/__init__.py module1.py module2.py

We can import a package like this:

From Package1 import Module1

From Package1 import Package2

Import Packag1.module1

Import Packag1.package2

__init__.py controls the import behavior of the package. If __init__.py is empty, then nothing can be done simply by importing the package.

>>> Import Package1

>>> Package1.module1

Traceback (most recent):

File "<pyshell#1>", line 1, in?

Package1.module1attributeerror: ' Module ' object has no attribute ' Module1 '

We need to pre-import the Module1 in __init__.py:

#文件 __init__.py

Import Module1

>>> Import Package1

>>> Package1.module1

<module ' Package1.module1 ' from ' Module.pyc ' >

__init__.py, called __all__. import all

from packagename import * 

example:  
#文件 __init__.py

__all__ = [' Module1 ', ' Module2 ', ' Package2 ']

The role of the __init__.py file in the Python module package