How can you profile a Python script?

Question

Project Euler and other coding contests often have a maximum time to run or people boast of how fast their particular solution runs. With python, sometimes the approaches are somewhat kludgey - i.e., adding timing code to `__main__`.What is a good way to profile how long a python program takes to run?

Answer 1

If doing the time calculation within the script itself is what's "kludgey", then another script can be written to do that. I hacked this up to do just that - certainly there's more eloquent ways to do something like this, but this gets an accurate time calculation

import time

import psutil

import sys

def foo(script_name):

t0 = time.time()

times = []

times.append(time.time())

for process in psutil.process_iter():

if 'python' in str(process.name) and script_name in str(process.cmdline()):

t = process.create_time()

return t, True

return time.time(), False

def main(script_name):

print('um hello')

r = False

while True:

a = foo(script_name)

r = a[1]

if r is True:

start = a[0]

else:

print('start the script already')

while r is True:

a = foo(script_name)

r = a[1]

if r is False:

end = time.time()

return round(start), round(end)

if __name__ == "__main__":

script_name = sys.argv[1]

start, end = main(script_name)

print('program ran for approx', end-start, 'seconds')