python - 从包中导入子包不起作用？

Question

I have the following files:

pack/__init__.py
pack/subpack/__init.__py
pack/subpack/mod2.py

And the following code fails on the last line:

from pack import * #should import everything
print subpack      #NameError: name 'subpack' is not defined

I would expect the subpackage to be imported - why is there a difference, and how can I overcome it? by "overcoming" I mean being able to refer to subpack without needing to write pack.subpack all the time.

Answer 1

You need to add

__all__ = ["mod1", "subpack"]

to pack/__init__.py . Without this line, mod1 would not be imported either, so I wonder what is going on there. See also the relevant section in Guido's tutorial .

Answer 2

Try adding "import subpack" in pack/__init__.py

If you have __all__ declared, make sure 'subpack' appears there.

Answer 3

Alternative suggestion for Python 3 is:

# pack/__init__.py
from . import subpack

And, as already was mentioned, if __all__ is declared, then add 'subpack' here.

And do not forget, that if you need NOT only:

print subpack

but also:

print subpack.mod2

then you need make similar operations in pack/subpack/__init.__py file