pi.py

import time
global più_o_meno, n, pi_greco
più_o_meno = 0
n = 1
pi_greco = 4 / n

start_time = time.time()
for index in range(100000000):
    n += 2
    if più_o_meno == 0:
        pi_greco = pi_greco - 4 / n
        più_o_meno = 1
    else:
        pi_greco = pi_greco + 4 / n
        più_o_meno = 0
print(pi_greco)
print("--- %s seconds ---" % (time.time() - start_time))

= RESTART: C:\Users\gtorr\AppData\Local\Programs\Python\Python37\pi_greco.py =
3.1415926545880506
--- 376.8734076023102 seconds --- 1.000.000.000 iterations

= RESTART: C:\Users\gtorr\AppData\Local\Programs\Python\Python37\pi_greco.py =
3.141592663589326
--- 36.41065573692322 seconds --- 100.000.000 iterations

= RESTART: C:\Users\gtorr\AppData\Local\Programs\Python\Python37\pi_greco.py =
3.1415927535897814
--- 3.5709989070892334 seconds --- 10.000.000 iterations

= RESTART: C:\Users\gtorr\AppData\Local\Programs\Python\Python37\pi_greco.py =
3.1415936535887745
--- 0.40099549293518066 seconds --- 1.000.000 iterations