http協(xié)議和多線程基礎(chǔ)
python中有一個(gè)第三方庫(kù)叫'requests'中提供了所有和http請(qǐng)求相關(guān)的函數(shù)
import requests
# 1.get請(qǐng)求
"""
get(url, params=None) - 發(fā)送請(qǐng)求獲取服務(wù)器返回的響應(yīng)
url - 請(qǐng)求地址, 字符串
params - 請(qǐng)求參數(shù), 字典
"""
# 方法一: (既適用于get也適用于post)
url = 'https://www.apiopen.top/satinApi'
params = {'type': 1, 'page': 2}
response = requests.get(url, params)
print(response)
# 方法二: 只能用于get請(qǐng)求
url = 'https://www.apiopen.top/satinApi?type=1&page=1'
response = requests.get(url)
# print(response)
# 2.獲取請(qǐng)求結(jié)果
# 1)響應(yīng)頭
# {'Server': 'nginx', 'Date': 'Thu, 15 Aug 2019 03:39:09 GMT', 'Content-Type': 'application/json;charset=utf-8', 'Transfer-Encoding': 'chunked', 'Connection': 'keep-alive', 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Methods': 'POST, GET, OPTIONS, DELETE', 'Access-Control-Max-Age': '3600', 'Access-Control-Allow-Headers': 'x-requested-with'}
print(response.headers)
# 2)響應(yīng)體(數(shù)據(jù))
# a.獲取二進(jìn)制對(duì)應(yīng)的原數(shù)據(jù)(數(shù)據(jù)本身是圖片、壓縮文件闰挡、視頻等文件數(shù)據(jù))
content = response.content
print(type(content))
# b.獲取字符類型的數(shù)據(jù)
text = response.text
print(type(text))
# c.獲取json數(shù)據(jù)(json轉(zhuǎn)換成python對(duì)應(yīng)的數(shù)據(jù))
json = response.json()
print(type(json))
print(json)
每個(gè)進(jìn)程默認(rèn)都有一條線程循签，這個(gè)線程叫主線程熄攘。其他線程叫子線程
threading模塊中Thread的對(duì)象就是線程對(duì)象嘁信，當(dāng)程序中需要子線程就創(chuàng)建Thread類的對(duì)象
import threading
from datetime import datetime
from time import sleep
def download(film_name):
# film_name = '魔童降世'
print('開始下載%s:%s' % (film_name, datetime.now()))
print(film_name, threading.current_thread())
sleep(5)
print('%s下載結(jié)束:%s' % (film_name, datetime.now()))
if __name__ == '__main__':
# download('魔童降世')
# download('掃毒2')
# download('怦然心動(dòng)')
# 1.創(chuàng)建線程對(duì)象
"""
Thread(target=None,args=()) - 創(chuàng)建并且返回一個(gè)子線程對(duì)象
target - 函數(shù)類型(function), 在線程啟動(dòng)的時(shí)候這個(gè)函數(shù)會(huì)在子線程中執(zhí)行
args - 元祖勤哗，元祖中的元素就是target對(duì)應(yīng)的函數(shù)在子線程中調(diào)用的時(shí)候傳的實(shí)參
"""
t1 = threading.Thread(target=download, args=('魔童降世',))
t2 = threading.Thread(target=download, args=('掃毒2',))
t3 = threading.Thread(target=download, args=('怦然心動(dòng)',))
print(threading.current_thread())
# 2.啟動(dòng)線程
"""
線程對(duì)象.start() - 讓線程去執(zhí)行線程中的任務(wù)
target(*args)
"""
t1.start()
t2.start()
t3.start()
線程中的任務(wù)執(zhí)行完成線程就結(jié)束; 程序出現(xiàn)異常結(jié)束的是線程抡爹，不是進(jìn)程
進(jìn)程中的所有線程就結(jié)束進(jìn)程才結(jié)束;
from threading import *
from datetime import datetime
from time import sleep
# 程序結(jié)束
# 1.聲明一個(gè)類繼承Thread
# 2.實(shí)現(xiàn)類中的run方法，這個(gè)方法中的代碼就是需要在子線程中執(zhí)行的代碼
# 3.需要子線程的時(shí)候就創(chuàng)建自己聲明的類的對(duì)象芒划，并且不需要任何參數(shù)
class DownloadThread(Thread):
def __init__(self, film_name):
super().__init__()
self.film_name = film_name
def run(self) -> None:
print('開始下載%s:%s' % (self.film_name, datetime.now()))
print(current_thread())
sleep(5)
print('%s下載結(jié)束:%s' % (self.film_name, datetime.now()))
if __name__ == '__main__':
t1 = DownloadThread('魔童降世')
t2 = DownloadThread('掃毒')
t1.start()
t2.start()
print([1, 2, 3][10])
print('==============')
from threading import *
from datetime import datetime
from time import *
from random import randint
def download(film_name):
print('開始下載%s：%s' % (film_name, datetime.now()))
sleep(randint(2, 7))
print('%s下載結(jié)束:%s' % (film_name, datetime.now()))
if __name__ == '__main__':
# 1.join的用法
"""
線程對(duì)象.join() - 當(dāng)前線程對(duì)象任務(wù)執(zhí)行完成后才能去執(zhí)行后面的代碼
"""
t1 = Thread(target=download, args=('魔童降世',))
t2 = Thread(target=download, args=('掃毒2',))
t3 = Thread(target=download, args=('怦然心動(dòng)',))
# 情況一:三個(gè)電影都下載完成才執(zhí)行'下載完成!!!'
# t1.start()
# t2.start()
# t3.start()
#
# t1.join()
# t2.join()
# t3.join()
# print('下載完成!!!!')
# 情況二: 電影1下載完成后才開始同時(shí)下載電影2和電影3
t1.start()
t1.join()
t2.start()
t3.start()
