list_set_demo.py

$ python
Python 3.8.2 (default, Jul 16 2020, 14:00:26) 
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import time
>>> commons_pids = list(range(1, 50))
>>> entity_pids = list(range(50, 100))
>>> def linear_scan():
...   for val in entity_pids:
...     if val in commons_pids:
...       return True
... 
>>> entity_pids_set = set(entity_pids)
>>> commons_pids_set = set(commons_pids)
>>> def set_scan():
...   return len(entity_pids_set & commons_pids_set) > 0
... 
>>> start = time.time(); len([set_scan() for i in range(1000)]); print(time.time() - start)
1000
0.0016851425170898438
>>> start = time.time(); len([linear_scan() for i in range(1000)]); print(time.time() - start)
1000
0.030255556106567383