python基础===requests学习笔记

这里有一个新的学习requests网站：http://docs.python-requests.org/zh_CN/latest/user/quickstart.html
2017/11/30

Requests is the only Non-GMO HTTP library for Python, safe for human consumption.

Note

The use of Python 3 is highly preferred over Python 2. Consider upgrading your applications and infrastructure if you find yourself still using Python 2 in production today. If you are using Python 3, congratulations — you are indeed a person of excellent taste. ———

>>> import requests

>>> r = requests.get('http://www.baidu.com')

Now, we have a response object called r. We can get all the information we need from this object.

For example, this is how you make an HTTP POST request:

>>> r = requests.post('http://xxxxx.com/post', data = {'key':'value'})

What about the other HTTP request types: PUT, DELETE, HEAD and OPTIONS? These are all just as simple:

>>> r = requests.put('http://xxxxxx.org/put', data = {'key':'value'})

>>> r = requests.delete('http://xxxxxxxx.org/delete')

>>> r = requests.head('http://xxxxxxx.org/get')

>>> r = requests.options('http://xxxxxxxxxx.org/get')

Passing Parameters In URLs

We often want to send some sort of data in the URL's query string.

As an example, if you wanted to pass key1=value1 and key2=value2 to httpbin.org/get, you would use the following code:

>>> payload = {'key1': 'value1', 'key2': 'value2'}

>>> r = requests.get('http://xxxxx.org/get', params=payload)

You can see that the URL has been correctly encoded；

>>> print(r.url)

http://httpbin.org/get?key2=value2&key1=value1

You can also pass a list of items as a value:

>>> payload = {'key1': 'value1', 'key2': ['value2', 'value3']}

>>> r = requests.get('http://xxxx.org/get', params=payload)

>>> print(r.url)

http://xxxx.org/get?key1=value1&key2=value2&key2=value3

Response Content

>>> import requests

>>> r = requests.get("http://www.baidu.com")

>>> r.text

'<!DOCTYPE html>\r\n<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge>

When you make a request, Requests makes educated guesses about the encoding of the response based on the HTTP headers. The text encoding guessed by Requests is used when you access r.text. You can find out what encoding Requests is using, and change it, using the r.encoding property:

>>> r.encoding

'ISO-8859-1'

>>> r.encoding = 'utf-8'

>>> r.text

'<!DOCTYPE html>\r\n<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=alway

If you change the encoding, Requests will use the new value of r.encoding whenever you call r.text.

If you have created your own encoding and registered it with the codecs module, you can simply use the codec name as the value of r.encoding and Requests will handle the decoding for you.

Binary Response Content

>>> r.content

b'<!DOCTYPE html>\r\n<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always

You can also access the response body as bytes, for non-text requests.

The gzip and deflate transfer-encodings are automatically decoded for you.

For example, to create an image from binary data returned by a request, you can use the following code:

>>> from PIL import Image

>>> from io import BytesIO

>>> i = Image.open(BytesIO(r.content))

JSON Response Content

>>> r = requests.get('https://api.github.com/events')

>>> r.json()

[{'id': '6736180556', 'type': 'PushEvent', 'actor': {'id': 14111893, 'login': 'rvitorgomes', 'display_login': 'rvitorgomes', 'gravatar_id': '', 'url': 'https://api.github.com/users/rvitorgomes', 'avatar_url': 'https://avatars.g

In case the JSON decoding fails, r.json() raises an exception. For example, if the response gets a 204 (No Content), or if the response contains invalid JSON, attempting r.json() raises ValueError: No JSON object could be decoded.

It should be noted that the success of the call to r.json() does not indicate the success of the response. Some servers may return a JSON object in a failed response (e.g. error details with HTTP 500). Such JSON will be decoded and returned. To check that a request is successful, use r.raise_for_status() or check r.status_code is what you expect.

Raw Response Content

In the rare case that you'd like to get the raw socket response from the server, you can access r.raw. If you want to do this, make sure you set stream=True in your initial request. Once you do, you can do this:

>>> r = requests.get('https://api.github.com/events', stream=True)

>>> r.raw

<requests.packages.urllib3.response.HTTPResponse object at 0x101194810>

>>> r.raw.read(10)

'\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03'

Custom Headers

>>> url = 'https://api.github.com/some/endpoint'

>>> headers = {'user-agent': 'my-app/0.0.1'}

>>> r = requests.get(url, headers=headers)

Note: Custom headers are given less precedence than more specific sources of information. For instance:

Authorization headers set with headers= will be overridden if credentials are specified in .netrc, which in turn will be overridden by the auth= parameter.
Authorization headers will be removed if you get redirected off-host.
Proxy-Authorization headers will be overridden by proxy credentials provided in the URL.
Content-Length headers will be overridden when we can determine the length of the content.

Furthermore, Requests does not change its behavior at all based on which custom headers are specified. The headers are simply passed on into the final request.

Note: All header values must be a string, bytestring, or unicode. While permitted, it's advised to avoid passing unicode header values.

More complicated POST requests

Typically, you want to send some form-encoded data — much like an HTML form. To do this, simply pass a dictionary to the data argument. Your dictionary of data will automatically be form-encoded when the request is made:

>>> payload = {'key1': 'value1', 'key2': 'value2'}

>>> r = requests.post("http://httpbin.org/post", data=payload)

>>> print(r.text)

{

  ...

  "form": {

    "key2": "value2",

    "key1": "value1"

  },

  ...

}

You can also pass a list of tuples to the data argument. This is particularly useful when the form has multiple elements that use the same key:

>>> payload = (('key1', 'value1'), ('key1', 'value2'))

>>> r = requests.post('http://httpbin.org/post', data=payload)

>>> print(r.text)

{

  ...

  "form": {

    "key1": [

      "value1",

      "value2"

    ]

  },

  ...

}

There are times that you may want to send data that is not form-encoded. If you pass in a string instead of a dict, that data will be posted directly.

For example, the GitHub API v3 accepts JSON-Encoded POST/PATCH data:

>>> import json

>>>import requests

>>> url = 'https://api.github.com/some/endpoint'

>>> payload = {'some': 'data'}

>>> r = requests.post(url, data=json.dumps(payload))

Instead of encoding the dict yourself, you can also pass it directly using the json parameter (added in version 2.4.2) and it will be encoded automatically:

>>> url = 'https://api.github.com/some/endpoint'

>>> payload = {'some': 'data'}

>>> r = requests.post(url, json=payload)
>>> print(r.text)
{
  "args": {}, 
  "data": "{\"key1\": \"value1\", \"key2\": \"value2\"}", 
  "files": {}, 
  "form": {},

POST a Multipart-Encoded File(多重编码文件)

Requests makes it simple to upload Multipart-encoded files:

>>> url = 'http://httpbin.org/post'

>>> files = {'file': open('report.xls', 'rb')}

>>> r = requests.post(url, files=files)

>>> r.text

{

  ...

  "files": {

    "file": "<censored...binary...data>"

  },

  ...

}

You can set the filename, content_type and headers explicitly:

>>> url = 'http://httpbin.org/post'

>>> files = {'file': ('report.xls', open('report.xls', 'rb'), 'application/vnd.ms-excel', {'Expires': '0'})}

>>> r = requests.post(url, files=files)

>>> r.text

{

  ...

  "files": {

    "file": "<censored...binary...data>"

  },

  ...

}

Response Status Codes

*详见之前博客，http响应码

>>> r = requests.get('http://www.baidu.com')

>>> r.status_code

200

Requests also comes with a built-in status code lookup object for easy reference:

>>> r.status_code == requests.codes.ok

True

If we made a bad request (a 4XX client error or 5XX server error response), we can raise it with Response.raise_for_status():

>>> bad_r = requests.get('http://httpbin.org/status/404')

>>> bad_r.status_code

404

>>> bad_r.raise_for_status()

Traceback (most recent call last):

  File "requests/models.py", line 832, in raise_for_status

    raise http_error

requests.exceptions.HTTPError: 404 Client Error

But, since our status_code for r was 200, when we call raise_for_status() we get:

>>> r.raise_for_status()

None

Response Headers

We can view the server's response headers using a Python dictionary:

>>> r.headers

{'Connection': 'keep-alive', 'Server': 'meinheld/0.6.1', 'Date': 'Thu, 19 Oct 2017 02:34:53 GMT', 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Credentials': 'true', 'X-Powered-By': 'Flask', 'X-Processed-Time': '0.000764846801758', 'Content-Length': '488', 'Via': '1.1 vegur'}

or,we can access the headers using any capitalization we want:

>>> r.headers["Date"]

'Thu, 19 Oct 2017 02:34:53 GMT'
>>> r.headers["Connection"]
'keep-alive'

If a response contains some Cookies, you can quickly access them:

>>> url = 'http://example.com/some/cookie/setting/url'

>>> r = requests.get(url)

>>> r.cookies['example_cookie_name']

'example_cookie_value'

我这里执行失败的，先记录下来吧

To send your own cookies to the server, you can use the cookies parameter:

>>> url = 'http://httpbin.org/cookies'

>>> cookies = dict(cookies_are = 'working')

>>> r = requests.get(url,cookies = cookies)

>>> r.text

'{\n  "cookies": {\n    "cookies_are": "working"\n  }\n}\n'

Cookies are returned in a RequestsCookieJar, which acts like a dict but also offers a more complete interface, suitable for use over multiple domains or paths. Cookie jars can also be passed in to requests:

>>> jar = requests.cookies.RequestsCookieJar()

>>> jar.set('tasty_cookie', 'yum', domain='httpbin.org', path='/cookies')

Cookie(version=0, name='tasty_cookie', value='yum', port=None, port_specified=False, domain='httpbin.org', domain_specified=True, domain_initial_dot=False, path='/cookies', path_specified=True, secure=False, expires=None, discard=True, comment=None, comment_url=None, rest={'HttpOnly': None}, rfc2109=False)

>>> jar.set('gross_cookie', 'blech', domain='httpbin.org', path='/elsewhere')

Cookie(version=0, name='gross_cookie', value='blech', port=None, port_specified=False, domain='httpbin.org', domain_specified=True, domain_initial_dot=False, path='/elsewhere', path_specified=True, secure=False, expires=None, discard=True, comment=None, comment_url=None, rest={'HttpOnly': None}, rfc2109=False)

>>> url = 'http://httpbin.org/cookies'

>>> r = requests.get(url, cookies=jar)

>>> r.text

'{\n  "cookies": {\n    "tasty_cookie": "yum"\n  }\n}\n'

Timeouts

>>> requests.get("http://www.baidu.com",timeout = 0.001)

Traceback (most recent call last):

  File "C:\Users\yangbo\AppData\Local\Programs\Python\Python36-32\lib\site-packages\urllib3\connection.py", line 141, in _new_conn

    (self.host, self.port), self.timeout, **extra_kw)

  File "C:\Users\yangbo\AppData\Local\Programs\Python\Python36-32\lib\site-packages\urllib3\util\connection.py", line 83, in create_connection

    raise err

  File "C:\Users\yangbo\AppData\Local\Programs\Python\Python36-32\lib\site-packages\urllib3\util\connection.py", line 73, in create_connection

    sock.connect(sa)

socket.timeout: timed out

python基础===requests学习笔记的更多相关文章

Python基础教程学习笔记：第一章基础知识
Python基础教程第二版学习笔记 1.python的每一个语句的后面可以添加分号也可以不添加分号:在一行有多条语句的时候,必须使用分号加以区分 2.查看Python版本号,在Dos窗口中输入“p ...
Python基础班学习笔记
本博客采用思维导图式笔记,所有思维导图均为本人亲手所画.因为本人也是初次学习Python语言所以有些知识点可能不太全. 基础班第一天学习笔记:链接基础班第二天学习笔记:链接基础班第三天学习笔记:链 ...
【学习笔记】Python基础教程学习笔记
教程视频网盘共享:http://pan.baidu.com/s/1hrTrR5E 03-python基础.if判断 print 输出数据 print("hahahah")----- ...
Python 基础语法学习笔记
以下运行结果均通过Python3.5版本实测! 1.列表转换为字典 a = ['a', 'b'] b = [1, 2] c = ['c','d'] print (dict([a,b,c])) 输出结果 ...
Python基础教程学习笔记：第二章列表和元组
1.序列中元素的索引: 第一个元素索引是0,第二个是1,依次递增最后一个元素索引是-1,倒数第二个是-2,依次递减 2.序列(Sequence)的种类: 列表(list).元组(tuple).字符串 ...
Requests:Python HTTP Module学习笔记（一）（转）
Requests:Python HTTP Module学习笔记(一) 在学习用python写爬虫的时候用到了Requests这个Http网络库,这个库简单好用并且功能强大,完全可以代替python的标 ...
Python基础知识总结笔记（四）函数
Python基础知识总结笔记(四)函数python中的函数函数中的参数变量作用域偏函数PFA递归函数高阶函数BIFs中的高阶函数匿名函数lambda闭包Closure装饰器Decorator函数式编程 ...
python网络爬虫学习笔记
python网络爬虫学习笔记 By 钟桓 9月 4 2014 更新日期:9月 4 2014 文章文件夹 1. 介绍: 2. 从简单语句中開始: 3. 传送数据给server 4. HTTP头-描写叙述 ...
linux基础命令学习笔记（二）
linux基础命令学习笔记(二) 1.kill :终止进程 kill pid (唯一标示一个进程) kill -9 强制终止 kill -15 命令未结束不能终止 # ps aux 查看所有进程 ...

随机推荐

【bzoj1700】Problem Solving 解题 dp
题目描述过去的日子里,农夫John的牛没有任何题目. 可是现在他们有题目,有很多的题目. 精确地说,他们有P (1 <= P <= 300) 道题目要做. 他们还离开了农场并且象普通人一 ...
CentOS vi编辑器简单备忘
1.常用编辑命令 dd 删除(剪切)光标所在整行 5dd 删除(剪切)从光标处开始的 5 行 yy 复制光标所在整行 5yy 复制从光标处开始的 5 行 n 显示搜索命令定位到的下一个字符串 N 显示 ...
1040: [ZJOI2008]骑士
首先是因为想学仙人掌图才来先拿这题热热身,结果&……竟然调了一个晚上我的傻叉!(其中一大半的时候是在郁闷hzwer和Greens的代码画风不一样,后来才发现一个用拓扑一个用树dp23333,以 ...
[NOIP2017]宝藏子集DP
题面:[NOIP2017]宝藏题面: 首先我们观察到,如果直接DP,因为每次转移的代价受上一个状态到底选了哪些边的影响,因此无法直接转移. 所以我们考虑分层DP,即每次强制现在加入的点的距离为k(可 ...
ocker nginx 配置反向代理和负载均衡
1. 获取及配置nginx 如果需要全站通过docker部署,那么nginx或许是不可或缺的.通过配置nginx,可以迅速实现负载均衡和反向代理服务.值得一提的是,docker官网恰好也有nginx镜 ...
POJ2945：Find the Clones——题解
http://poj.org/problem?id=2945 还是trie树……对于结束标记累加并且开个数组记录一下即可. #include<cstdio> #include<cst ...
BZOJ2659 [Beijing wc2012]算不出的算式【数形结合】
题目链接 BZOJ2659 题解真没想到,, 观察式子 \[\sum\limits_{k = 1}^{\frac{p - 1}{2}} \lfloor \frac{kq}{p} \rfloor\] ...
HDOJ(HDU).1003 Max Sum (DP)
HDOJ(HDU).1003 Max Sum (DP) 点我挑战题目算法学习-–动态规划初探题意分析给出一段数字序列,求出最大连续子段和.典型的动态规划问题. 用数组a表示存储的数字序列,sum ...
webpack css压缩方案
css-loader原有的minimize选项在1.0.0版本已经移除,不能使用其进行css压缩. 目前可行的css压缩方案有: 1. postcss-loader with cssnano or u ...
middle中间件
什么事中间件: http://www.crazyant.net/1001.html dd

python基础===requests学习笔记

Passing Parameters In URLs

Response Content

Binary Response Content

JSON Response Content

Raw Response Content

Custom Headers

More complicated POST requests

POST a Multipart-Encoded File(多重编码文件)

Response Status Codes

Response Headers

Cookies

Timeouts

python基础===requests学习笔记的更多相关文章

随机推荐

热门专题