timing_demo.py

from contextlib import contextmanager
from datetime import datetime
import time


def test_pass():
    print('.')
    time.sleep(0.5)
    return True

def test_FAIL():
    print('X')
    time.sleep(0.5)
    return False

@contextmanager
def time_code(desc):
   t1 = datetime.now()
   yield()
   t2 = datetime.now()
   print("{} took {} seconds".format(desc, (t2 - t1).seconds))


with time_code("failure with conds second"):
	valid = True
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_FAIL()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()

with time_code("pass with conds second"):
	valid = True
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()
	valid = valid and test_pass()

with time_code("failure with conds first"):
	valid = True
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_FAIL() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid

with time_code("pass with conds first"):
	valid = True
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid
	valid = test_pass() and valid


# Result:
# failure with conds second took 1 seconds
# pass with conds second took 4 seconds
# failure with conds first took 4 seconds
# pass with conds first took 4 seconds