I am intermittently getting an error when I call MPRester. Unfortunately, it’s hard for me to say exactly why because I don’t get this error every time I call MPRester. The error says:
Traceback (most recent call last):
File “/home/ubuntu/foo/bar.py”, line 410, in foobar
with MPRester(param.MP_KEY) as m:
File “/home/ubuntu/.local/lib/python3.8/site-packages/pymatgen/ext/matproj.py”, line 205, in init
if “MAPI_DB_VERSION” not in d:
TypeError: argument of type ‘NoneType’ is not iterable
The only thing I can think of is that it might have to do with the fact that I am using multithreading/multiprocessing to call MPRester multiple times in parallel to speed up my database querying.