run_with_save.py

import pathlib # Handle paths (https://pbpython.com/pathlib-intro.html)
import numpy as np


def run_simulation(n=1000):
    x = np.random.randn(n)
    y = np.random.randn(n,n) @ x
    simulation_results = dict(x=x, y=y)
    return simulation_results


# Define output folder
output_folder = pathlib.Path('output')

# Create folder if not exists (create parents too)
output_folder.mkdir(parents=True, exist_ok=True)

# Define output path (simulation filename)
output_path = output_folder / 'simulation.npz'

completed = output_path.exists()

if not completed:
    simulation_results = run_simulation()

    np.savez(str(output_path), **simulation_results)
else:
    simulation_results = dict(np.load(str(output_path)))


print(simulation_results['x'].mean(), simulation_results['x'].std())
print(simulation_results['y'].mean(), simulation_results['y'].std())