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python requests简介
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更为强大的库requests是为了更加方便地实现爬虫操作,有了它 ， Cookies 、登录验证、代理设置等操作都不是 .
一、安装requests模块(cmd窗口执行)
pip3 install requests
二、requests的基本方法
import requests
response=requests.get("https://www.baidu.com/")
print(type(response)) #<class 'requests.models.Response'> response类型
print(response.status_code) #200 获取状态码
print(response.text) #获取网页源码
print(response.content) #获取网页源码
print(response.cookies) #获取网页cookies ，Req u estsCookieJar
print(response.headers) #获取请求头
三、推荐一个测试网址：http://httpbin.org测试请求网站，可以随便捣鼓（其他请求方式）
import requests
r=requests.post("http://httpbin.org/post")
print(r.text) #打印post请求的头部信息
r=requests.put("http://httpbin.org/post")
r=requests.delete("http://httpbin.org/post")
r=requests.options("http://httpbin.org/post")
这里分别用 post （）、 put （）、 delete （）等方法实现了 POST 、 PUT 、 DELETE 等请求 。
四、get 请求
查看get请求包含的请求信息
import requests
r=requests.get("http://httpbin.org/get")
print(r.text) #打印get请求信息
结果显示：
{
"args": {},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"origin": "119.123.196.143",
"url": "http://httpbin.org/get"
}
结果显示说明：一个请求信息应该包含了请求头、ip地址、URL等信息。
（1）请求添加额外信息
方法一：？key=value&key2=value2... (?：表示起始，&：表示和)
r= requests.get("http://httpbin.org/get?name=germey&age=22")
import requests
r= requests.get("http://httpbin.org/get?name=germey&age=22")
print(r.text)
方法一示例
{
"args": {
"age": "",
"name": "germey"
},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"origin": "119.123.196.143",
"url": "http://httpbin.org/get?name=germey&age=22"
}
方法一结果
通过运行结果可以判断，请求的链接自动被构造成了：http://httpbin.org/get?name=germey&age=22
方法二：利用get 里面参数params，可以将请求信息编译加载到url中（ 推荐使用 ）
import requests
data={
"name":"germey",
"age":22
}
r=requests.get("http://httpbin.org/get",params=data)
print(r.text)
结果显示：
{
"args": {
"age": "",
"name": "germey"
},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"origin": "119.123.196.143",
"url": "http://httpbin.org/get?name=germey&age=22"
}
方法二结果
结果都构造了：http://httpbin.org/get?name=germey&age=22， 方法二比较实用
（2）从网页请求到的请求信息都是json格式字符串，转换成字典dict,使用 .json()；
如果不是Json格式，则报错：JSON。decodeJSONDecodeError异常
import requests
r=requests.get("http://httpbin.org/get")
print(type(r.text)) #查看请求头数据类型
print(r.text) #打印请求信息
#r.json() 将json字符串转换为字典
print(type(r.json()))#转换为dict，打印数据类型
<class 'str'>
{
"args": {},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"origin": "119.123.196.143",
"url": "http://httpbin.org/get"
} <class 'dict'>
结果
结果显示：请求信息是<str>；r.json（）后的数据是<dict>
五、get方法请求抓取网页实例
(1)成功获取知乎的网页信息
# 请求知乎
import requests
#构建请求要求信息
data={
"type":"content",
"q":"赵丽颖"
}
url="https://www.zhihu.com/search"
#构建请求的ip和服务器信息
headers={
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36" ,
"origin": "119.123.196.143",
}
response=requests.get(url,params=data,headers=headers)
print(response.text)
添加搜索信息和headrs信息
这里我们加入了 headers 信息，其中包含了 User- Agent 字段信息， 也就是浏览器标识信息 。 如果
不加这个 ，知乎会禁止抓取,data构造了一个请求搜索信息.
(2)github站点图标下载
import requests
r=requests.get(" https://github.com/favicon.ico")
print(r.text)
print(r.content)
with open("github.ico","wb") as f:
f.write(r.content)
打印图标示例
(3)请求头信息headers
{
"args": {},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"origin": "119.123.196.143",
"url": "https://httpbin.org/get"
}
(4)抓取github图标
r.text 得到的数据是字符串类型
r.content 得到的数据是bytes类型数据
import requests
r = requests.get("https://github.com/favicon.ico")
print('text',r.text)#获取到字符串
print('content',r.content) #获取的是二进制
import requests
r=requests.get(" https://github.com/favicon.ico")
print(r.text)
print(r.content)
with open("gg.ico","wb") as f:
f.write(r.content)
github图片写入
六、post请求
带data信息请求
import requests
data ={
'name' :'pig',
'age':18
}
r = requests.post('http://httpbin.org/post', data=data)
print(r.text)
{
"args": {},
"data": "",
"files": {},
"form": {
"age": "",
"name": "pig"
},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Content-Length": "",
"Content-Type": "application/x-www-form-urlencoded",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.20.1"
},
"json": null,
"origin": "119.123.198.80",
"url": "http://httpbin.org/post"
}
post请求信息
七、请求状态码
1、100状态码：信息状态码
2、200状态码：成功状态码
3、300状态吗：重定向状态码
4、400状态码：客户端错误状态码
5、500状态码：服务器错误状态码
import requests
import re def get(url,session):
headers={
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.100 Safari/537.36",
"Host": "book.douban.com"
}
response=session.get(url,headers=headers)
return response.content.decode("utf-8") def parse(path,data,session):
res=session.get(data,timeout=2)
with open(path,"wb") as f:
f.write(res.content) if __name__ == '__main__':
obj=re.compile('<img src="(?P<picture>.*?)"')
session = requests.session()
html=get("https://book.douban.com/",session)
pic_url_list=obj.findall(html,re.S)
n=1 for pic_url in pic_url_list:
print(pic_url)
try:
path=r"book_picture/"+f"{n}"+".jpg"
parse(path,pic_url,session)
n+=1 except Exception as e:
print(e)
豆瓣图片爬取实例
#coding=utf-8
import requests
import os
import re def getHtml(url):
headers={
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
"Cookie": "BDqhfp=%E5%90%8D%E8%83%9C%E5%8F%A4%E8%BF%B9%26%26-10-1undefined%26%260%26%261; BAIDUID=3E9EFDBD86FBFCF2DA4C32A06482351C:FG=1; BIDUPSID=E013F7397D0EF0F46FFAF97FC8A7F349; PSTM=1543903169; pgv_pvi=2584268800; delPer=0; PSINO=7; BDRCVFR[5VG_cZ6c41T]=9xWipS8B-FspA7EnHc1QhPEUf; ZD_ENTRY=baidu; BDRCVFR[dG2JNJb_ajR]=mk3SLVN4HKm; indexPageSugList=%5B%22%E5%90%8D%E8%83%9C%E5%8F%A4%E8%BF%B9%22%5D; cleanHistoryStatus=0; BDRCVFR[-pGxjrCMryR]=mk3SLVN4HKm; BCLID=7951205421696906576; BDSFRCVID=_rLOJeC629zHWkc9ByJPtBGK9T-me2jTH6bH27NMSSL8H8ptFoAvEG0PjM8g0KubkDpOogKK3gOTH4PF_2uxOjjg8UtVJeC6EG0P3J; H_BDCLCKID_SF=tJI8_DLytD_3JRcFDDTb-tCqMfTM2n58a5IX3buQX-od8pcNLTDKeJIn3UR2qxj8WHRJ5q3cfx-VDJK4MlO1j4DnDGJwWlJgBnb7VPJ23J7Nfl5jDh38XjksD-Rt5tnR-gOy0hvctb3cShPm0MjrDRLbXU6BK5vPbNcZ0l8K3l02VKO_e4bK-Tr3jaDetU5; H_PS_PSSID=; BDORZ=FFFB88E999055A3F8A630C64834BD6D0; userFrom=blog.csdn.net",
"Host": "image.baidu.com",
"Upgrade-Insecure-Requests":"",
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36"
}
page = requests.get(url,headers=headers)
html = page.content.decode()
return html if __name__ == '__main__': msg=input("请输入搜索内容<如苍老师>:")
os.mkdir(msg)
html = getHtml(f"https://image.baidu.com/search/index?ct=201326592&cl=2&st=-1&lm=-1&nc=1&ie=utf-8&tn=baiduimage&ipn=r&rps=1&pv=&word={msg}&hs=0&oriquery=%E5%90%8D%E8%83%9C%E5%8F%A4%E8%BF%B9&ofr=%E5%90%8D%E8%83%9C%E5%8F%A4%E8%BF%B9&z=0&ic=0&face=0&width=0&height=0&latest=0&s=0&hd=0©right=0&selected_tags=%E7%AE%80%E7%AC%94%E7%94%BB") obj=re.compile('"thumbURL":"(?P<pic>.*?)"',re.S)
pic_list=obj.findall(html)
n=1
for pic_url in pic_list:
print(pic_url)
try:
data=requests.get(pic_url,timeout=2)
path=f"{msg}/"+f"{n}"+".jpg"
with open(path,"wb") as f:
print("-----------正在下载图片----------")
f.write(data.content)
n+=1
print("----------下载完成----------")
except Exception as e:
print(e)
百度图片静态爬取（待优化）
