perf.py

# coding: utf-8
import math
def map_loop():
    list(map(math.sin, range(20000000)))

def for_loop():
    r = []
    for i in range(20000000):
        r.append(math.sin(i))

def local_var_for_loop():
    r = []
    local_append = r.append
    local_sin = math.sin
    for i in range(20000000):
        local_append(local_sin(i))

def bigger_step_for_loop():
    r = []
    local_append = r.append
    local_sin = math.sin
    for i in range(0, 20000000, 4):
        local_append(local_sin(i))
        local_append(local_sin(i+1))
        local_append(local_sin(i+2))
        local_append(local_sin(i+3))

import time

class Timer:
  def __init__(self):
    self.reset()
  def reset(self):
    self.start = 0.0
    self.end = 0.0
    self.interval = 0.0
  def set(self):
    self.start = time.time()
  def stop(self, num):
    self.end = time.time()
    self.interval = (self.end - self.start)/num
    print('costs time %f s' % self.interval)

number_tasks = 20000000

timer = Timer()
print('I: using for loop')
timer.set()
for i in range(10):
    for_loop()
timer.stop(10)

print('I: using map()')
timer.set()
for i in range(10):
    map_loop()
timer.stop(10)

print('I: using local_var_for_loop')
timer.set()
for i in range(10):
    local_var_for_loop()
timer.stop(10)

print('I: using map outside function')
timer.set()
for i in range(10):
    result = list(map(math.sin, range(20000000)))
timer.stop(10)