转载: https://www.cnblogs.com/lei0213/p/6957508.html
内置的状态码
简介
Requests是用python语言基于urllib编写的，采用的是Apache2 Licensed开源协议的HTTP库，Requests它会比urllib更加方便，可以节约我们大量的工作。
一、安装
pip快速安装
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pip install requests
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二、使用
1、先上一串代码
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import
requests
response
=
requests.get(
"https://www.baidu.com"
)
print
(
type
(response))
print
(response.status_code)
print
(
type
(response.text))
response.enconding
=
"utf
-
8
'
print
(response.text)
print
(response.cookies)
print
(response.content)
print
(response.content.decode(
"utf-8"
))
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response.text返回的是Unicode格式，通常需要转换为utf-8格式，否则就是乱码。response.content是二进制模式，可以下载视频之类的，如果想看的话需要decode成utf-8格式。
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
2、一大推请求方式
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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"
)
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基本GET:
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import
requests
url
=
'https://www.baidu.com/'
response
=
requests.get(url)
print
(response.text)
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带参数的GET请求：
如果想查询http://httpbin.org/get页面的具体参数，需要在url里面加上，例如我想看有没有Host=httpbin.org这条数据，url形式应该是http://httpbin.org/get?Host=httpbin.org
下面提交的数据是往这个地址传送data里面的数据。
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import
requests
url
=
'http://httpbin.org/get'
data
=
{
'name'
:
'zhangsan'
,
'age'
:
'25'
}
response
=
requests.get(url,params
=
data)
print
(response.url)
print
(response.text)
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Json数据：
从下面的数据中我们可以得出，如果结果：
1、requests中response.json()方法等同于json.loads（response.text）方法
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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())
|
获取二进制数据
在上面提到了response.content，这样获取的数据是二进制数据，同样的这个方法也可以用于下载图片以及
视频资源
添加header
首先说，为什么要加header（头部信息）呢？例如下面，我们试图访问知乎的登录页面（当然大家都你要是不登录知乎，就看不到里面的内容），我们试试不加header信息会报什么错。
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import
requests
url
=
'https://www.zhihu.com/'
response
=
requests.get(url)
response.encoding
=
"utf-8"
print
(response.text)
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结果：
提示发生内部服务器错误（也就说你连知乎登录页面的html都下载不下来）。
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<html><body><h1>
500
Server Error<
/
h1>
An internal server error occured.
<
/
body><
/
html>
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如果想访问就必须得加headers信息。
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import
requests
url
=
'https://www.zhihu.com/'
headers
=
{
'User-Agent'
:
'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36'
}
response
=
requests.get(url,headers
=
headers)
print
(response.text)
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基本post请求：
通过post把数据提交到url地址，等同于一字典的形式提交form表单里面的数据
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import
requests
url
=
'http://httpbin.org/post'
data
=
{
'name'
:
'jack'
,
'age'
:
'23'
}
response
=
requests.post(url,data
=
data)
print
(response.text)
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结果：
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{
"args"
: {},
"data"
: "",
"files"
: {},
"form"
: {
"age"
:
"23"
,
"name"
:
"jack"
},
"headers"
: {
"Accept"
:
"*/*"
,
"Accept-Encoding"
:
"gzip, deflate"
,
"Connection"
:
"close"
,
"Content-Length"
:
"16"
,
"Content-Type"
:
"application/x-www-form-urlencoded"
,
"Host"
:
"httpbin.org"
,
"User-Agent"
:
"python-requests/2.13.0"
},
"json"
: null,
"origin"
:
"118.144.137.95"
,
"url"
:
"http://httpbin.org/post"
}
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响应：
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import
requests
response
=
requests.get(
"http://www.baidu.com"
)
#打印请求页面的状态（状态码）
print
(
type
(response.status_code),response.status_code)
#打印请求网址的headers所有信息
print
(
type
(response.headers),response.headers)
#打印请求网址的cookies信息
print
(
type
(response.cookies),response.cookies)
#打印请求网址的地址
print
(
type
(response.url),response.url)
#打印请求的历史记录（以列表的形式显示）
print
(
type
(response.history),response.history)
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内置的状态码：
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'),
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import
requests
response
=
requests.get(
'http://www.jianshu.com/404.html'
)
# 使用request内置的字母判断状态码
#如果response返回的状态码是非正常的就返回404错误
if
response.status_code !
=
requests.codes.ok:
print
(
'404'
)
#如果页面返回的状态码是200，就打印下面的状态
response
=
requests.get(
'http://www.jianshu.com'
)
if
response.status_code
=
=
200
:
print
(
'200'
)
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request的高级操作
文件上传
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import
requests
url
=
"http://httpbin.org/post"
files
=
{
"files"
:
open
(
"test.jpg"
,
"rb"
)}
response
=
requests.post(url,files
=
files)
print
(response.text)
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结果：
获取cookie
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import
requests
response
=
requests.get(
'https://www.baidu.com'
)
print
(response.cookies)
for
key,value
in
response.cookies.items():
print
(key,
'=='
,value)
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会话维持
cookie的一个作用就是可以用于模拟登陆，做会话维持
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import
requests
session
=
requests.session()
session.get(
'http://httpbin.org/cookies/set/number/12456'
)
response
=
session.get(
'http://httpbin.org/cookies'
)
print
(response.text)
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证书验证
1、无证书访问
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import
requests
response
=
requests.get(
'https://www.12306.cn'
)
# 在请求https时，request会进行证书的验证，如果验证失败则会抛出异常
print
(response.status_code)
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报错：
关闭证书验证
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import
requests
# 关闭验证，但是仍然会报出证书警告
response
=
requests.get(
'https://www.12306.cn'
,verify
=
False
)
print
(response.status_code)
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为了避免这种情况的发生可以通过verify=False，但是这样是可以访问到页面结果
消除验证证书的警报
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from
requests.packages
import
urllib3
import
requests
urllib3.disable_warnings()
response
=
requests.get(
'https://www.12306.cn'
,verify
=
False
)
print
(response.status_code)
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手动设置证书
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import
requests
response
=
requests.get(
'https://www.12306.cn'
, cert
=
(
'/path/server.crt'
,
'/path/key'
))
print
(response.status_code)
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代理设置
1、设置普通代理
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import
requests
proxies
=
{
"http"
:
"http://127.0.0.1:9743"
,
"https"
:
"https://127.0.0.1:9743"
,
}
response
=
requests.get(
"https://www.taobao.com"
, proxies
=
proxies)
print
(response.status_code)
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2、设置用户名和密码代理
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import
requests
proxies
=
{
"http"
:
"http://user:password@127.0.0.1:9743/"
,
}
response
=
requests.get(
"https://www.taobao.com"
, proxies
=
proxies)
print
(response.status_code)
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设置socks代理
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安装socks模块 pip3 install
'requests[socks]'
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import
requests
proxies
=
{
'http'
:
'socks5://127.0.0.1:9742'
,
'https'
:
'socks5://127.0.0.1:9742'
}
response
=
requests.get(
"https://www.taobao.com"
, proxies
=
proxies)
print
(response.status_code)
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超时设置
通过timeout参数可以设置超时的时间
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import
requests
from
requests.exceptions
import
ReadTimeout
try
:
# 设置必须在500ms内收到响应，不然或抛出ReadTimeout异常
response
=
requests.get(
"http://httpbin.org/get"
, timeout
=
0.5
)
print
(response.status_code)
except
ReadTimeout:
print
(
'Timeout'
)
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认证设置
如果碰到需要认证的网站可以通过requests.auth模块实现
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import
requests
from
requests.auth
import
HTTPBasicAuth
<br>
#方法一
r
=
requests.get(
'http://120.27.34.24:9001'
, auth
=
HTTPBasicAuth(
'user'
,
'123'
))<br>
#方法二<br>r = requests.get('http://120.27.34.24:9001', auth=('user', '123'))
print
(r.status_code)
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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
这里列举了一些常用的异常继承关系，详细的可以看：
http://cn.python-requests.org/zh_CN/latest/_modules/requests/exceptions.html#RequestException
通过下面的例子进行简单的演示
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import
requests
from
requests.exceptions
import
ReadTimeout, ConnectionError, RequestException
try
:
response
=
requests.get(
"http://httpbin.org/get"
, timeout
=
0.5
)
print
(response.status_code)
except
ReadTimeout:
print
(
'Timeout'
)
except
ConnectionError:
print
(
'Connection error'
)
except
RequestException:
print
(
'Error'
)
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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
