Python程序设计例题

Posted 2020-11-30 Jokerˇ

例一：蒙特卡罗方法求解 π 值

 1 from random import random
 2 from math import sqrt
 3 from time import clock
 4 DARTS=1000
 5 hits=0.0
 6 clock()
 7 for i in range(1,DARTS+1):
 8     x,y=random(),random()
 9     dist=sqrt(x**2+y**2)
10     if dist<=1.0:
11         hits=hits+1
12 pi=4*(hits/DARTS)
13 print("pi值是{}.".format(pi))
14 print("运行时间是：{:5.5}s".format(clock()))

运行结果：pi值是3.216.

　　　　　运行时间是：0.0034431s
                 [Finished in 0.5s]

例二：贵阳天气：

原文：https://blog.csdn.net/weixin_42358077/article/details/95188483

import requests
from bs4 import BeautifulSoup
import re

def get_page(url):
    try:
        kv = {\'user-agent\':\'Mozilla/5.0\'}
        r = requests.get(url,headers = kv)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return \'错误\'

def parse_page(html, return_list):
    soup = BeautifulSoup(html, \'html.parser\')
    day_list = soup.find(\'ul\', \'t clearfix\').find_all(\'li\')
    for day in day_list:
        date = day.find(\'h1\').get_text()
        wea = day.find(\'p\',  \'wea\').get_text()
        if day.find(\'p\', \'tem\').find(\'span\'):
                hightem = day.find(\'p\', \'tem\').find(\'span\').get_text()
        else:
                hightem = \'\'
        lowtem = day.find(\'p\', \'tem\').find(\'i\').get_text() 
   
        win = re.findall(\'(?<= title=").*?(?=")\', str(day.find(\'p\',\'win\').find(\'em\')))
        wind = \'-\'.join(win)
        level = day.find(\'p\', \'win\').find(\'i\').get_text()
        return_list.append([date, wea, lowtem, hightem, wind, level])
    #return return_list

def print_res(return_list):
    tplt = \'{0:<10}\\t{1:^10}\\t{2:^10}\\t{3:{6}^10}\\t{4:{6}^10}\\t{5:{6}^5}\'
    print(tplt.format(\'日期\', \'天气\', \'最低温\', \'最高温\', \'风向\', \'风力\',chr(12288)))
    for i in return_list:
        print(tplt.format(i[0], i[1],i[2],i[3],i[4],i[5],chr(12288)))

def main():
    url = \'http://www.weather.com.cn/weather/101260101.shtml\'
    html = get_page(url)
    wea_list = []
    parse_page(html, wea_list)
    print_res(wea_list)

if __name__ == \'__main__\':
    main()

　　运行结果：

 

 例三：输出标题：

1 import requests
2 from bs4 import BeautifulSoup
3 r=requests.get(\'http://www.baidu.com\')
4 r.encoding=None
5 result=r.text
6 bs=BeautifulSoup(result,\'html.parser\')
7 print(bs.title.text)

运行结果：

百度一下，你就知道
[Finished in 1.6s]