四大解析器（BeautifulSoup、PyQuery、lxml、正則）性能比較

用標題中的四種方式解析網頁，比較其解析速度。固然比較結果數值與電腦配置，python版本都有關係，但整體差異不會很大。

下面是個人結果，lxml xpath最快，bs4最慢

==== Python version: 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 17:00:18) [MSC v.1900 64 bit (AMD64)] =====

==== Total trials: 10000 =====
bs4 total time: 5.5
pq total time: 0.9
lxml (cssselect) total time: 0.8
lxml (xpath) total time: 0.5
regex total time: 1.1 (doesn't find all p)

　如下是測試代碼

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

"""
@Datetime: 2019/3/13
@Author: Zhang Yafei
"""
import re
import sys
import time
import requests
from lxml.html import fromstring
from pyquery import PyQuery as pq
from bs4 import BeautifulSoup as bs


headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36'}


def Timer():
    a = time.time()
    while True:
        c = time.time()
        yield time.time() - a
        a = c

# ################# start request #################
timer = Timer()
url = "https://www.python.org/"
html = requests.get(url, headers=headers).text
num = 10000
print('\n==== Python version: %s =====' % sys.version)
print('\n==== Total trials: %s =====' % num)
next(timer)

# ################# bs4 #########################
soup = bs(html, 'lxml')
for x in range(num):
    paragraphs = soup.findAll('p')
t = next(timer)
print('bs4 total time: %.1f' % t)
# ################ pyquery #######################
d = pq(html)
for x in range(num):
    paragraphs = d('p')
t = next(timer)
print('pq total time: %.1f' % t)
# ############### lxml css #########################
tree = fromstring(html)
for x in range(num):
    paragraphs = tree.cssselect('p')
t = next(timer)
print('lxml (cssselect) total time: %.1f' % t)
# ############## lxml xpath #######################
tree = fromstring(html)
for x in range(num):
    paragraphs = tree.xpath('.//p')
t = next(timer)
print('lxml (xpath) total time: %.1f' % t)
# ############### re ##########################
for x in range(num):
    paragraphs = re.findall('<[p ]>.*?</p>', html)
t = next(timer)
print('regex total time: %.1f (doesn\'t find all p)\n' % t)　

測試代碼二

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

"""
@Datetime: 2019/3/13
@Author: Zhang Yafei
"""
import functools
import re
import sys
import time

import requests
from bs4 import BeautifulSoup as bs
from lxml.html import fromstring
from pyquery import PyQuery as pq


def timeit(fun):
    @functools.wraps(fun)
    def wrapper(*args, **kwargs):
        start_time = time.time()
        res = fun(*args, **kwargs)
        print('運行時間爲%.6f' % (time.time() - start_time))
        return res

    return wrapper


@timeit  # time1 = timeit(time)
def time1(n):
    return [i * 2 for i in range(n)]


# ################# start request #################
url = "https://www.taobao.com/"
html = requests.get(url).text
num = 10000
print('\n==== Python version: %s =====' % sys.version)
print('\n==== Total trials: %s =====' % num)


@timeit
def bs4_test():
    soup = bs(html, 'lxml')
    for x in range(num):
        paragraphs = soup.findAll('p')
    print('bs4 total time:')


@timeit
def pq_test():
    d = pq(html)
    for x in range(num):
        paragraphs = d('p')
    print('pq total time:')


@timeit
def lxml_css():
    tree = fromstring(html)
    for x in range(num):
        paragraphs = tree.cssselect('p')
    print('lxml (cssselect) total time:')


@timeit
def lxml_xpath():
    tree = fromstring(html)
    for x in range(num):
        paragraphs = tree.xpath('.//p')
    print('lxml (xpath) total time:')


@timeit
def re_test():
    for x in range(num):
        paragraphs = re.findall('<[p ]>.*?</p>', html)
    print('regex total time:')


if __name__ == '__main__':
    bs4_test()
    pq_test()
    lxml_css()
    lxml_xpath()
    re_test()

　　測試結果

==== Python version: 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 17:00:18) [MSC v.1900 64 bit (AMD64)] =====

==== Total trials: 10000 =====
bs4 total time:
運行時間爲9.049424
pq total time:
運行時間爲0.899639
lxml (cssselect) total time:
運行時間爲0.841596
lxml (xpath) total time:
運行時間爲0.619440
regex total time:
運行時間爲1.207861