一、urllib
1、请求 urillib.reques.urlopen(url = url, data = post_data, [time_out]*)
(1)get类请求
from urllib import request
response = request.urlopen("http://www.baidu.com")
print(response.read().decode("utf-8"))
(2)post类请求
from urllib import request
from urllib import parse
data = bytes(parse.urlencode({"yan":18}), encoding = ("utf-8"))
response = request.urlopen(url = "http://httpbin.org/post", data = data)
print(response.read())
2、响应
from urllib import request
response = request.urlopen("http://www.baidu.com")
print(response.read().decode("utf-8"))#获取响应体
print(response.status)#获取状态码
print(response.getheaders())#获取响应头
print(response.getheader("Server"))#获取响应头中的特定项
3、请求
(1)请求参数扩展
from urllib import request
from urllib import parse
data = bytes(parse.urlencode({"name":"Han Yan"}), encoding = "utf-8")
header = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36",
"Host": "httpbin.org"}
req = request.Request(url = "http://httpbin.org/post", data = data, headers = header, method = "POST")
response = request.urlopen(req, timeout = 5)
print(response.read().decode("utf-8"))
4、Cookie
(1)直接输出
from http import cookiejar
from urllib import request
cookie = cookiejar.CookieJar()
handler = request.HTTPCookieProcessor(cookie)
opener = request.build_opener(handler)
response = opener.open("http://www.baidu.com")
for item in cookie:
print(item.name + " : " + item.value)
(2)存为文本文件
from http import cookiejar
from urllib import request
file_name = "cookie.txt"
cookie = cookiejar.MozillaCookieJar(file_name)#cookie = cookiejar.LWPCookieJar(file_name)
handle = request.HTTPCookieProcessor(cookie)
opener = request.build_opener(handle)
response = opener.open("http://www.baidu.com")
cookie.save()
with open(file_name, 'r') as f:
for line in f:
print(line.rstrip())
5、异常处理
(1)404找不到网页【父类error.URLERROR成员reason】
from urllib import request, error
try:
response = request.urlopen("http://www.bilibili.com/dwdwd")
print(response.status)
except error.URLError as e:
print("ERROR REASON: " + e.reason)
(2)time out超时
from urllib import request, error
import socket
try:
response = request.urlopen("http://www.bilibili.com/dwdwd", timeout = 0.001)
print(response.status)
except error.URLError as e:
if isinstance(e.reason, socket.timeout):
print("ERROR REASON:", e.reason, sep = " ")
(3)子类error.HTTPERROR三个成员code, reason, headers}
from urllib import request, error
import socket
try:
response = request.urlopen("http://www.bilibili.com/dwdwd")
print(response.status)
except error.HTTPError as e:
print("ERROR REASON:" , e.reason, sep = " ")
print("ERROR CODE:", e.code, sep = " ")
print("ERROR HEADER:", e.headers, sep = "\n*\n", end = "*\n")
except error.URLError as e:
if isinstance(e.reason, socket.timeout):
print("ERROR REASON:", e.reason, sep = " ")
6、URL解析
(1)urlparse
from urllib.parse import urlparse
url = "https://www.bilibili.com/video/av19057145?p=8#comment"
res = urlparse(url, scheme = "http", allow_fragments = True)
#若url含协议,scheme忽略
#alllow_fragments指定是否合并fragments内容
print(type(res), res, sep = "\n")
(2)urljoin(url1, url2)使用url2中的字段覆盖url1中的字段,返回覆盖后的url
(3)urlencode(dict)将字典转换为get类型的参数格式
from urllib import parse
base_url = "https://www.bilibili.com/video/av19057145"
para = {"p":8}
url = base_url + "?" + parse.urlencode(para)
print(url)
二、requests库
1、get请求
(1)get()请求:参数在url中,可以使用字典存储
import requests
argus = {"name":"Han Yan",
"age":25}
base_url = "http://httpbin.org"
response = requests.get(base_url + "/get", argus)
print(response.text)
(2)get响应返回值可以通过json()方法解析,格式与调用json.loads()相同
import requests, json
response = requests.get("http://httpbin.org/get")
print(type(response.json()), type(json.loads(response.text)))
(3)保存图片
注意:.text成员为str类,.content成员为bytes(二进制流)类,调用open(file_name, “wb”)创建写入
import requests
response = requests.get("http://www.zimuxia.cn/wp-content/uploads/2020/03/LadyWP.jpg")
with open("img.jpg", "wb") as img:
img.write(response.content)
img.close()
(4)增加请求头
部分站点,无请求头访问会出现状态码400/500
import requests
header = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36"}
request = requests.get("https://www.zhihu.com/", headers = header)
print(request.status_code)
注意:部分网站仅添加header中的User_Agent仍然403,考虑添加referer
referer = "http://image.baidu.com/search/index?tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=&st=-1&fm=result&fr=&sf=1&fmq=1586774219869_R&pv=&ic=&nc=1&z=&hd=&latest=©right=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&sid=&word=%E7%8C%AB"
header = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36", "Referer":referer}
print(requests.get("http://img1.imgtn.bdimg.com/it/u=3750061867,603167218&fm=26&gp=0.jpg", headers = header).status_code)
# 200
2、post请求
(1)data参数传递
import requests
data = {"name":"Han Yan",
"age":25}
response = requests.post("http://httpbin.org/post", data = data)
print(response.text)
3、响应
(1)response属性
import requests
header = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36"}
response = requests.get("http://www.zhihu.com", headers = header)
print(type(response.status_code))
print(type(response.headers))
print(type(response.url))
print(type(response.cookies))
print(type(response.history))
(2)状态码判断
requests.codes = {
# Informational.
100: ('continue',),
101: ('switching_protocols',),
102: ('processing',),
103: ('checkpoint',),
122: ('uri_too_long', 'request_uri_too_long'),
200: ('ok', 'okay', 'all_ok', 'all_okay', 'all_good', '\\o/', '✓'),
201: ('created',),
202: ('accepted',),
203: ('non_authoritative_info', 'non_authoritative_information'),
204: ('no_content',),
205: ('reset_content', 'reset'),
206: ('partial_content', 'partial'),
207: ('multi_status', 'multiple_status', 'multi_stati', 'multiple_stati'),
208: ('already_reported',),
226: ('im_used',),
# Redirection.
300: ('multiple_choices',),
301: ('moved_permanently', 'moved', '\\o-'),
302: ('found',),
303: ('see_other', 'other'),
304: ('not_modified',),
305: ('use_proxy',),
306: ('switch_proxy',),
307: ('temporary_redirect', 'temporary_moved', 'temporary'),
308: ('permanent_redirect',
'resume_incomplete', 'resume',), # These 2 to be removed in 3.0
# Client Error.
400: ('bad_request', 'bad'),
401: ('unauthorized',),
402: ('payment_required', 'payment'),
403: ('forbidden',),
404: ('not_found', '-o-'),
405: ('method_not_allowed', 'not_allowed'),
406: ('not_acceptable',),
407: ('proxy_authentication_required', 'proxy_auth', 'proxy_authentication'),
408: ('request_timeout', 'timeout'),
409: ('conflict',),
410: ('gone',),
411: ('length_required',),
412: ('precondition_failed', 'precondition'),
413: ('request_entity_too_large',),
414: ('request_uri_too_large',),
415: ('unsupported_media_type', 'unsupported_media', 'media_type'),
416: ('requested_range_not_satisfiable', 'requested_range', 'range_not_satisfiable'),
417: ('expectation_failed',),
418: ('im_a_teapot', 'teapot', 'i_am_a_teapot'),
421: ('misdirected_request',),
422: ('unprocessable_entity', 'unprocessable'),
423: ('locked',),
424: ('failed_dependency', 'dependency'),
425: ('unordered_collection', 'unordered'),
426: ('upgrade_required', 'upgrade'),
428: ('precondition_required', 'precondition'),
429: ('too_many_requests', 'too_many'),
431: ('header_fields_too_large', 'fields_too_large'),
444: ('no_response', 'none'),
449: ('retry_with', 'retry'),
450: ('blocked_by_windows_parental_controls', 'parental_controls'),
451: ('unavailable_for_legal_reasons', 'legal_reasons'),
499: ('client_closed_request',),
# Server Error.
500: ('internal_server_error', 'server_error', '/o\\', '✗'),
501: ('not_implemented',),
502: ('bad_gateway',),
503: ('service_unavailable', 'unavailable'),
504: ('gateway_timeout',),
505: ('http_version_not_supported', 'http_version'),
506: ('variant_also_negotiates',),
507: ('insufficient_storage',),
509: ('bandwidth_limit_exceeded', 'bandwidth'),
510: ('not_extended',),
511: ('network_authentication_required', 'network_auth', 'network_authentication')}
4、post()添加files参数实现文件上传
import requests
file = {"file":open("img.jpg", "rb")}
response = requests.post(url = "http://httpbin.org/post", files = file)
print(response.text)
5、会话维持
(1)若设置cookie后再次访问,会出现cookie丢失的情况,因为两次访问是独立的
import requests
response = requests.get("http://httpbin.org/cookies/set/number/996649")
response = requests.get("http://httpbin.org/cookies")
print(response.text)
(2)使用requests.session()方法访问,实现会话维持
import requests
session = requests.session()
session.get("http://httpbin.org/cookies/set/number/996649")
response = session.get("http://httpbin.org/cookies")
print(response.text)
6、证书验证
(1)关闭证书验证
import requests
requests.packages.urllib3.disable_warnings()
response = requests.get(url = "", verify = False)
print(response.status_code)
(2)增加cert()参数提供证书
7、代理设置
import requests
proxy = {}
response = requests.get(url = "https://www.baidu.com", proxies = proxy)
8、超时设置
import requests
from requests.exceptions import ConnectTimeout
try:
response = requests.get("http://httpbin.org/get", timeout = 0.1)
print(response.status_code)
except ConnectTimeout:
print("timeout!")
9、遇到登录验证设置认证
import requests
auth = {"1033":"yanhan"}
response = requests.get(url= "", auth = auth)
print(respnse.text)
10、requests包Exceptions相关官方文档
Exceptions
exception requests.RequestException(*args, **kwargs)[source]
There was an ambiguous exception that occurred while handling your request.
exception requests.ConnectionError(*args, **kwargs)[source]
A Connection error occurred.
exception requests.HTTPError(*args, **kwargs)[source]
An HTTP error occurred.
exception requests.URLRequired(*args, **kwargs)[source]
A valid URL is required to make a request.
exception requests.TooManyRedirects(*args, **kwargs)[source]
Too many redirects.
exception requests.ConnectTimeout(*args, **kwargs)[source]
The request timed out while trying to connect to the remote server.
Requests that produced this error are safe to retry.
exception requests.ReadTimeout(*args, **kwargs)[source]
The server did not send any data in the allotted amount of time.
exception requests.Timeout(*args, **kwargs)[source]
The request timed out.
Catching this error will catch both ConnectTimeout and ReadTimeout errors.
import requests
from requests import exceptions
try:
response = requests.get("http://httpbin.org/get", timeout = 0.5)
if response.status_code == requests.codes.ok:
print("Request successfully")
except exceptions.Timeout:
print("Timeout!")
except exceptions.ConnectionError:
print("Connectionerror!")