circular import when importing SpaceGroup

[jacksund]

@janosh It looks like the issue from #2470 was reintroduced into pymatgen v2023.11.12

To Reproduce:

from pymatgen.symmetry.groups import SpaceGroup

The traceback:

Traceback (most recent call last):

  Cell In[1], line 1
    from pymatgen.symmetry.groups import SpaceGroup

  File ~\AppData\Local\anaconda3\envs\simmate_dev\Lib\site-packages\pymatgen\symmetry\groups.py:21
    from pymatgen.core.operations import SymmOp

  File ~\AppData\Local\anaconda3\envs\simmate_dev\Lib\site-packages\pymatgen\core\__init__.py:23
    from pymatgen.core.structure import IMolecule as IMolecule

  File ~\AppData\Local\anaconda3\envs\simmate_dev\Lib\site-packages\pymatgen\core\structure.py:47
    from pymatgen.symmetry.maggroups import MagneticSpaceGroup

  File ~\AppData\Local\anaconda3\envs\simmate_dev\Lib\site-packages\pymatgen\symmetry\maggroups.py:17
    from pymatgen.symmetry.groups import SymmetryGroup, in_array_list

ImportError: cannot import name 'SymmetryGroup' from partially initialized module 'pymatgen.symmetry.groups' (most likely due to a circular import) (C:\Users\nxj625\AppData\Local\anaconda3\envs\simmate_dev\Lib\site-packages\pymatgen\symmetry\groups.py)

As an extra, this code actually works fine in case someone needs a quick-fix:

from pymatgen.symmetry import groups   # dummy import that makes others behave normally
from pymatgen.symmetry.groups import SpaceGroup