Don't use user-supplied integers on dicts or sets on Python: >>> {i for i in range(10000)} Takes 0.005s >>> {i * sys.hash_info.modulus for i in range(10000)}

Don't use user-supplied integers on dicts or sets on Python: >>> {i for i in range(10000)} Takes 0.005s >>> {i * sys.hash_info.modulus for i in range(10000)} Takes 0.76s