Why might we use "from . import * " in Python

Question

what is the full meaning for this statement in python ?

from . import *

I have seen such code in some application like this one for minecraft map file reader.

https://github.com/twoolie/NBT/blob/master/nbt/__init__.py

Answer 1

When you write from mypkg import *, Python looks at the __all__ variable of the __init__.py file of the package, which is believed to be filled with names of submodules. It then loads all the submodules listed in that variable into the local namespace. If __all__ does not exist, it loads instead all the symbols defined in the __init__.py file (including submodules explicitely imported in that file, but not every submodule of the package). Reference.

You use from . when you are in a submodule inside a package (intra-package reference). This refers to the package the submodule is in, whatever name it has. So from . import * does exactly what is described above, but for the package the submodule is part of. Note that if the submodule is itself listed in the __all__ variable, then it will fail due to dependency loop.

Concerning your example, the module is itself the __init__.py and also defines a __all__ variable, so it is lucky that Python doesn't crash on dependency loop. The line is useless anyway, as the local code doesn't make use of these modules.