Traceback (most recent call last): File "extract_variables.py", line 5, in a = L.variables["a"] KeyError: 'a' Traceback (most recent call last): File "extract_variables.py", line 5, in a = L.variables["a"] File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 619, in variables for v in self._parse_element_list(output): File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 728, in _parse_element_list lines = output[6:-3] TypeError: 'NoneType' object is not subscriptable Traceback (most recent call last): File "extract_variables.py", line 5, in a = L.variables["a"] File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 619, in variables for v in self._parse_element_list(output): File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 728, in _parse_element_list lines = output[6:-3] TypeError: 'NoneType' object is not subscriptable Traceback (most recent call last): File "extract_variables.py", line 5, in a = L.variables["a"] File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 619, in variables for v in self._parse_element_list(output): File "/home/pacos/.local/lib/python3.8/site-packages/lammps/pylammps.py", line 728, in _parse_element_list lines = output[6:-3] TypeError: 'NoneType' object is not subscriptable