switch_vs_dict.py

# -*- coding: utf-8 -*-

import numpy as np
import time

n_choices = 18


def switch_fun(x):
    if x == 0:
        return 0
    elif x == 1:
        return 1
    elif x == 2:
        return 2
    elif x == 3:
        return 3
    elif x == 4:
        return 4
    elif x == 5:
        return 5
    elif x == 6:
        return 6
    elif x == 7:
        return 7
    elif x == 8:
        return 8
    elif x == 9:
        return 9
    elif x == 10:
        return 10
    elif x == 11:
        return 11
    elif x == 12:
        return 12
    elif x == 13:
        return 13
    elif x == 14:
        return 14
    elif x == 15:
        return 15
    elif x == 16:
        return 16
    elif x == 17:
        return 17


_switch_dict = dict((ii, ii) for ii in range(n_choices))


def dict_fun(x):
    return _switch_dict.get(x)


n_repeat = 1000
tags = np.arange(500) % n_choices
times = np.zeros((2, n_repeat))
for ii, fun in enumerate((switch_fun, dict_fun)):
    for jj in range(n_repeat):
        t0 = time.time()
        for tag in tags:
            fun(tag)
        times[ii, jj] = time.time() - t0

times = np.median(times, axis=1)
print('%0.1fx speedup for dict access' % (times[0] / times[1]))