`get_resolved_dos()` Inconsistent Behavior with `atom_indices` Type

[yuyuanjingxuan]

Summary

There is a bug in the get_resolved_dos() method when plotting the DOS via the electronic_structure object. The function behaves differently depending on whether atom_indices is a native Python int or a numpy.int64.

pyiron Version and Platform

pyiron: '0.5.2'
pyiron_atomistics: '0.6.12'

Expected Behavior

The get_resolved_dos() method should return DOS data with consistent behavior regardless of whether atom_indices is a numpy.int64 or a native Python int.

Actual Behavior

When passing an atom_indices of type numpy.int64, the method returns an unexpected output shape.

es.get_resolved_dos(atom_indices=132, orbital_indices=orb_dict['d']).shape
# Output: (8000,)

k = atom_list[0]
es.get_resolved_dos(atom_indices=k, orbital_indices=orb_dict['d']).shape
# Output: (9, 8000)

type(k), type(132)
# Output: (numpy.int64, int)

In this case, 132 is a native Python int, and k is a numpy.int64, leading to different behaviors despite representing the same index.

Steps to Reproduce

1. Load an electronic structure object:

   es = job_load.get_electronic_structure()

2. Call get_resolved_dos() using a Python int as atom_indices:

   es.get_resolved_dos(atom_indices=132, orbital_indices=orb_dict['d']).shape
   # Expected Output: (8000,)

3. Call get_resolved_dos() using a numpy.int64 as atom_indices:

   k = atom_list[0]
   es.get_resolved_dos(atom_indices=k, orbital_indices=orb_dict['d']).shape
   # Output: (9, 8000)

Further Information, Files, and Links

The issue arises because the following code does not correctly identify numpy.int64:

if isinstance(atom_indices, int):

A suggested fix is to replace this line with:

if isinstance(atom_indices, numbers.Integral):

This will ensure both numpy.int64 and native int types are handled correctly. Thanks to @pmrv for this suggestion!