7、关于requests项目

 

 

1    开发哲学

Beautiful is better than ugly.(美丽优于丑陋)

Explicit is better than implicit.(直白优于含蓄)

Simple is better than complex.(简单优于复杂)

Complex is better than complicated.(复杂优于繁琐)

Readability counts.(可读性很重要)

2    遵循的协议

Requests 的发布许可为 Apache2 License.

因为项目发行于 GPL 协议之后，就不能用于任何本身没开源的商业产品中。

    MIT、BSD、ISC、Apache2 许可都是优秀的替代品，它们允许你的开源软件自由应用在私有闭源软件中。

3    requests信息

    requests是一个Python的网络请求库，和urllib、httplib之流相比起来最大的优点就是好用。requests还支持https验证并且是线程安全的。

下载地址

https://github.com/kennethreitz/requests/tarball/master

安装后在eclipse如果还没有识别，需要在PYTHON解释器中加上

Properties-> PyDev Interpreter

Click here to configure an Interpreter not list.

4    简单使用

import requests

r = requests.get('https://www.python.org')

r.status_code

print r.status_code

直接执行即可。

或者如下：

import requests

r = requests.get('https://api.github.com/user', auth=('user','pass'))

print r.status_code

print r.headers['content-type']

print r.encoding

print r.text

print r.json()

5    代码

因为官方提供的项目信息并不是特别多，一个一个解决不免枯燥乏味，为此想到一个实战办法。以具体实例为切入点一点一点阅读。

5.1 Request(主要接口)

示例代码如下：

import requests

r = requests.get('https://github.com/timeline.json')

print r

r = requests.post("http://httpbin.org/post")

print r

r = requests.put("http://httpbin.org/put")

print r

r = requests.delete("http://httpbin.org/delete")

print r

r = requests.head("http://httpbin.org/get")

print r

r = requests.options("http://httpbin.org/get")

print r

我们来学习一下

import 导入我们安装的requests包

然后调用函数get，post，put，delete，head，options

Requests 所有的功能都可以通过以下 7 个方法访问

最后都返回一个Response对象的实例。

5.1.1 get

在api.py文件中，内如如下：

def get(url, params=None, **kwargs):

    r"""Sends a GETrequest.

    :paramurl: URL for the new:class:`Request` object.

    :paramparams: (optional)Dictionary or bytes to be sent in the query string for the :class:`Request`.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

   kwargs.setdefault('allow_redirects',True)

    return request('get', url, params=params, **kwargs)

发送GET请求，参数有url,params,kwargs.

       url参数Request对象。Params是字典。Kwargs是可选参数，被requests调用。

       返回Response对象。

       最后调用request函数。

5.1.2 post

def post(url, data=None, json=None, **kwargs):

    r"""Sends a POSTrequest.

    :paramurl: URL for the new:class:`Request` object.

    :param data: (optional) Dictionary (willbe form-encoded), bytes, or file-like object to send in the body of the:class:`Request`.

    :paramjson: (optional) jsondata to send in the body of the :class:`Request`.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

    return request('post', url, data=data, json=json, **kwargs)

5.1.3 put

def put(url, data=None, **kwargs):

    r"""Sends a PUTrequest.

    :paramurl: URL for the new:class:`Request` object.

    :param data: (optional) Dictionary (willbe form-encoded), bytes, or file-like object to send in the body of the:class:`Request`.

    :paramjson: (optional) jsondata to send in the body of the :class:`Request`.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

    return request('put', url, data=data, **kwargs)

和get基本一致。

5.1.4 delete

def delete(url, **kwargs):

    r"""Sends a DELETErequest.

    :paramurl: URL for the new:class:`Request` object.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

    return request('delete', url, **kwargs)

和get基本一致。

5.1.5 head

def head(url, **kwargs):

    r"""Sends a HEADrequest.

    :paramurl: URL for the new:class:`Request` object.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

   kwargs.setdefault('allow_redirects',False)

    return request('head', url, **kwargs)

和get基本一致。

5.1.6 options

def options(url, **kwargs):

    r"""Sends a OPTIONSrequest.

    :paramurl: URL for the new:class:`Request` object.

    :param \*\*kwargs: Optionalarguments that ``request`` takes.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

   """

   kwargs.setdefault('allow_redirects',True)

    return request('options', url, **kwargs)

和get基本一致。

5.1.7 request

def request(method, url, **kwargs):

    """Constructs andsends a :class:`Request <Request>`.

    :param method: method for the new:class:`Request` object.

    :paramurl: URL for the new:class:`Request` object.

    :paramparams: (optional)Dictionary or bytes to be sent in the query string for the :class:`Request`.

    :param data: (optional) Dictionary or listof tuples ``[(key, value)]`` (will be form-encoded), bytes, or file-like objectto send in the body of the :class:`Request`.

    :paramjson: (optional) jsondata to send in the body of the :class:`Request`.

    :param headers: (optional) Dictionary ofHTTP Headers to send with the :class:`Request`.

    :param cookies: (optional)Dict orCookieJar object to send with the :class:`Request`.

    :param files: (optional) Dictionary of``'name': file-like-objects`` (or ``{'name': file-tuple}``) formultipartencoding upload.

       ``file-tuple`` can be a 2-tuple ``('filename',fileobj)``,3-tuple ``('filename', fileobj, 'content_type')``

       or a 4-tuple ``('filename',fileobj, 'content_type',custom_headers)``, where ``'content-type'`` is a string

       defining the content type of the given file and ``custom_headers`` adict-likeobject containing additional headers

       to add for the file.

    :paramauth: (optional) Authtuple to enable Basic/Digest/Custom HTTP Auth.

    :param timeout: (optional) How long towait for the server to send data

       before giving up, as a float, or a :ref:`(connect timeout, read

       timeout) <timeouts>` tuple.

    :type timeout: float or tuple

    :param allow_redirects: (optional)Boolean. Enable/disable GET/OPTIONS/POST/PUT/PATCH/DELETE/HEAD redirection.Defaults to ``True``.

    :type allow_redirects:bool

    :paramproxies: (optional)Dictionary mapping protocol to the URL of the proxy.

    :param verify: (optional) Either aboolean, in which case it controls whether we verify

           the server's TLS certificate, or a string, in which case it must be apath

           to a CA bundle to use. Defaults to ``True``.

    :param stream: (optional) if ``False``,the response content will be immediatelydownloaded.

    :paramcert: (optional) if String,path to ssl client cert file (.pem). If Tuple, ('cert','key') pair.

    :return::class:`Response <Response>` object

    :rtype: requests.Response

 

   Usage::

     >>> import requests

     >>> req = requests.request('GET','http://httpbin.org/get')

     <Response [200]>

   """

    # By using the 'with' statement weare sure the session is closed, thus we

    # avoid leaving sockets open whichcan trigger a ResourceWarning in some

    # cases, and look like a memory leakin others.

    with sessions.Session() as session:

       return session.request(method=method,url=url, **kwargs)

打开session。那么我们来看下这个session对象。

5.2     session

位于session.py文件中。

这个模块提供Session对象来管理cookie持久化，连接池和配置.

示例：

import requests

s = requests.Session()

print s.get('http://httpbin.org/get')

或者：

import requests

with requests.Session() as s:

     print s.get('http://httpbin.org/get')

5.3     身份验证

包含request的认证句柄。

5.4     exceptions异常

异常定义在exceptions.py文件中。

从urllib3中导入HTTPError，命名为BaseHTTPError

定义了RequestException类。

6     模块

6.1 包含关键模块urllib3

    Requests允许你发送纯天然，植物饲养的 HTTP/1.1 请求，无需手工劳动。你不需要手动为 URL 添加查询字串，也不需要对 POST 数据进行表单编码。Keep-alive 和 HTTP 连接池的功能是 100% 自动化的，一切动力都来自于根植在 Requests 内部的 urllib3

7    附录A

7.1 httplib2

    httplib2尽管名声在外，但它文档欠佳，而且基本操作要写的代码依旧太多。对于 httplib2，要写一个现代 HTTP 客户端要跟一吨低级麻烦事打交道，实在是件苦差事。但无论如何，还是直接使用 Requests 吧。Kenneth Reitz 是一个很负责的作者，他能把简单的东西做简单。httplib2 感觉像是一个学术产物，而 Requests 才真的是一个人们可以在生产系统中使用的东西。