Use of OMP_NUM_THREADS=1 for Python Multiprocessing

Question

I heard that using OMP_NUM_THREADS=1 before calling a Python script that use multiprocessing make the script faster.

Is it true or not ? If yes, why so

Answer 1

Resolved in comments:

OMP_NUM_THREADS is an option for OpenMP, a C/C++/Fortran API for doing multi-threading within a process.
It's unclear how that's even related to Python multiprocessing.
Is your Python program calling modules written in C that use OpenMP internally? – Wyzard