3,Requests-网络请求
Requests是用python语言基于urllib编写的
总体功能演示
import requests
response = requests.get("https://www.baidu.com")
print(type(response)) <class 'requests.models.Response'>
print(response.status_code)
print(type(response.text))
print(response.text) 字符串
print(response.cookies)
print(response.content) 二进制
print(response.content.decode("utf-8")) 字符串注意:
网站如果直接response.text会出现乱码的问题，使用response.content返回的数据格式是二进制格式，然后通过decode()转换为utf-8，解决了通过response.text直接返回显示乱码的问题.
请求发出后，Requests 会基于 HTTP 头部对响应的编码作出有根据的推测。当你访问 response.text 之时，Requests 会使用其推测的文本编码。你可以找出 Requests 使用了什么编码，并且能够使用 response.encoding 属性来改变它.
response =requests.get("http://www.baidu.com")
response.encoding="utf-8"
print(response.text)不管是通过response.content.decode("utf-8)的方式还是通过response.encoding="utf-8"的方式都可以避免乱码的问题发生
自动检测编码方式
pip install chardet
response =requests.get("http://www.baidu.com")
response.encoding=chardet.detect(response.content)['encoding'] 直接获取全部响应
print(response.text)
另外一种流模式
response =requests.get("http://www.baidu.com", stream=True)
response.raw.read(10请求方式
import requests
requests.post("http://httpbin.org/post")
requests.put("http://httpbin.org/put")
requests.delete("http://httpbin.org/delete")
requests.head("http://httpbin.org/get")
requests.options("http://httpbin.org/get")1.请求方式
带参数的GET请求
import requests
response = requests.get("http://httpbin.org/get?name=zhaofan&age=23")
print(response.text)
2,在URL查询字符串传递数据
通常我们会通过httpbin.org/get?key=val方式传递。Requests模块允许使用params关键字传递参数，以一个字典来传递这些参数
import requests
data = {
"name":"zhaofan",
"age":22
}
response = requests.get("http://httpbin.org/get",params=data)
print(response.url)
print(response.text)解析Json
import requests
import json
response = requests.get("http://httpbin.org/get")
print(type(response.text))
print(response.json())
print(json.loads(response.text))
print(type(response.json()))添加header
import requests
headers = {
"User-Agent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36"
}
response =requests.get("https://www.zhihu.com",headers=headers)
print(response.text)
基本POST请求
import requests
data = {
"name":"zhaofan",
"age":23
}
response = requests.post("http://httpbin.org/post",data=data)
print(response.text)
响应
import requests
response = requests.get("http://www.baidu.com")
print(type(response.status_code),response.status_code)
print(type(response.headers),response.headers) response.headers.get('content-type')
print(type(response.cookies),response.cookies)
print(type(response.url),response.url)
print(type(response.history),response.history) 状态码
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')
示例
import requests
response= requests.get("http://www.baidu.com")
if response.status_code == requests.codes.ok:
print("访问成功")
获取cookies
import requests
response = requests.get("http://www.baidu.com")
print(response.cookies)
for key,value in response.cookies.items():
print(key+"="+value)
##
for cookie in response.cookie.keys()
print(response.cookies.get(cookie))
##自定义cookie
cookies = dict(name='qiye', age='10')
response = requests.get("http://www.baidu.com",cookies=cookies)会话保持
import requests
s = requests.Session()
s.get("http://httpbin.org/cookies/set/number/123456")
response = s.get("http://httpbin.org/cookies")
print(response.text)
datas={'name':'hhh', 'password':'xxxx'}
r=s.post(url,data=datas)
证书验证
import requests
from requests.packages import urllib3
urllib3.disable_warnings()
response = requests.get("https://www.12306.cn",verify=False)
print(response.status_code)
代理设置
import requests
proxies= {
"http":"http://127.0.0.1:9999",
"https":"http://127.0.0.1:8888"
}
response = requests.get("https://www.baidu.com",proxies=proxies)
print(response.text)
#### 或通过环境变量配置
HTTP_PROXY HTTPS_PROXY
##设置账号和密码
proxies = {
"http":"http://user:[email protected]:9999"
}
## 通过sokces
## pip install "requests[socks]"
proxies= {
"http":"socks5://127.0.0.1:9999",
"https":"sockes5://127.0.0.1:8888"
}超时设置
通过timeout参数可以设置超时的时间
r= request.get(url,timeout=2)认证
需要认证的网站可以通过requests.auth模块实现
import requests
from requests.auth import HTTPBasicAuth
response = requests.get("http://120.27.34.24:9001/",auth=HTTPBasicAuth("user","123"))
print(response.status_code)
##另一种方式
import requests
response = requests.get("http://120.27.34.24:9001/",auth=("user","123"))
print(response.status_code)
异常处理
关于reqeusts的异常在这里可以看到详细内容：
http://www.python-requests.org/en/master/api/#exceptions 所有的异常都是在requests.excepitons中
从源码我们可以看出RequestException继承IOError,
HTTPError，ConnectionError,Timeout继承RequestionException
ProxyError，SSLError继承ConnectionError
ReadTimeout继承Timeout异常
捕获异常顺序
import requests
from requests.exceptions import ReadTimeout,ConnectionError,RequestException
try:
response = requests.get("http://httpbin.org/get",timout=0.1)
print(response.status_code)
except ReadTimeout:
print("timeout")
except ConnectionError:
print("connection Error")
except RequestException:
print("error")首先被捕捉的异常是timeout,当把网络断掉的haul就会捕捉到ConnectionError，如果前面异常都没有捕捉到，最后也可以通过RequestExctption捕捉到