如何优雅的封装requests

搭建接口自动化测试框架，一般都要对post/get请求做封装。

一般的封装过程是，

class MyRequest:
    def my_post():
        """do something"""
        requests.post(url=url, json=data, headers=self.headers)
    def my_get():
        """do something"""
        requests.get(url=url, params=params, headers=self.headers)

然而，借助装饰器，可以实现更优雅的封装。

在这之前，先打开requests.api.request，看看源码。

# -*- coding: utf-8 -*-

"""
requests.api
~~~~~~~~~~~~

This module implements the Requests API.

:copyright: (c) 2012 by Kenneth Reitz.
:license: Apache2, see LICENSE for more details.
"""

from . import sessions


def request(method, url, **kwargs):
    """Constructs and sends a :class:`Request <Request>`.

    :param method: method for the new :class:`Request` object.
    :param url: URL for the new :class:`Request` object.
    :param params: (optional) Dictionary, list of tuples or bytes to send
        in the query string for the :class:`Request`.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
    :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
    :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
    :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding 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`` a dict-like object containing additional headers
        to add for the file.
    :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
    :param timeout: (optional) How many seconds to wait 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
    :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
    :param verify: (optional) Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use. Defaults to ``True``.
    :param stream: (optional) if ``False``, the response content will be immediately downloaded.
    :param cert: (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', 'https://httpbin.org/get')
      <Response [200]>
    """

    # By using the 'with' statement we are sure the session is closed, thus we
    # avoid leaving sockets open which can trigger a ResourceWarning in some
    # cases, and look like a memory leak in others.
    with sessions.Session() as session:
        return session.request(method=method, url=url, **kwargs)


def get(url, params=None, **kwargs):
    r"""Sends a GET request.

    :param url: URL for the new :class:`Request` object.
    :param params: (optional) Dictionary, list of tuples or bytes to send
        in the query string for the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    kwargs.setdefault('allow_redirects', True)
    return request('get', url, params=params, **kwargs)


def options(url, **kwargs):
    r"""Sends an OPTIONS request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    kwargs.setdefault('allow_redirects', True)
    return request('options', url, **kwargs)


def head(url, **kwargs):
    r"""Sends a HEAD request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    kwargs.setdefault('allow_redirects', False)
    return request('head', url, **kwargs)


def post(url, data=None, json=None, **kwargs):
    r"""Sends a POST request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) json data to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

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


def put(url, data=None, **kwargs):
    r"""Sends a PUT request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) json data to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

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


def patch(url, data=None, **kwargs):
    r"""Sends a PATCH request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) json data to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

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


def delete(url, **kwargs):
    r"""Sends a DELETE request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

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

首先定义了1个request函数。

后面定义了get/options/head/post/put/patch/delete 6个函数。

后面的6个函数，内部都在调用第一个request函数。只是传参不同。

显而易见，源码已经按不同的method做了一次封装了。

我们自己的封装就不要再定义my_get/my_post了，直接在这层封装上，加入我们自己的额外代码就好了。

装饰器，就能把我们自己的额外代码，优雅的加上去。

装饰器，长这样，

def decorator(post):
    def wrap():
        post()
    return wrap

如果加到post函数上去，

@decorator
def post()

就等价于，

post = decorator(post)

看到没有，我们可以在decorator里面搞事情了！

在搞事情前，先建个MyRequest，把requests.api.request的代码原封不动的沾过来，加上我们的装饰器@method

from requests.api import request

class MyRequest:
    
    #  def request可以不用添加
    
    @method
    def get(self, url, params=None, **kwargs):
        r"""Sends a GET request.

        :param url: URL for the new :class:`Request` object.
        :param params: (optional) Dictionary, list of tuples or bytes to send
            in the query string for the :class:`Request`.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

        kwargs.setdefault('allow_redirects', True)
        return request('get', url, params=params, **kwargs)

    @method
    def options(self, url, **kwargs):
        r"""Sends an OPTIONS request.

        :param url: URL for the new :class:`Request` object.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

        kwargs.setdefault('allow_redirects', True)
        return request('options', url, **kwargs)

    @method
    def head(self, url, **kwargs):
        r"""Sends a HEAD request.

        :param url: URL for the new :class:`Request` object.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

        kwargs.setdefault('allow_redirects', False)
        return request('head', url, **kwargs)

    @method
    def post(self, url, data=None, json=None, **kwargs):
        r"""Sends a POST request.

        :param url: URL for the new :class:`Request` object.
        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
            object to send in the body of the :class:`Request`.
        :param json: (optional) json data to send in the body of the :class:`Request`.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """
        return request('post', url, data=data, json=json, **kwargs)

    @method
    def put(self, url, data=None, **kwargs):
        r"""Sends a PUT request.

        :param url: URL for the new :class:`Request` object.
        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
            object to send in the body of the :class:`Request`.
        :param json: (optional) json data to send in the body of the :class:`Request`.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

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

    @method
    def patch(self, url, data=None, **kwargs):
        r"""Sends a PATCH request.

        :param url: URL for the new :class:`Request` object.
        :param data: (optional) Dictionary, list of tuples, bytes, or file-like
            object to send in the body of the :class:`Request`.
        :param json: (optional) json data to send in the body of the :class:`Request`.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

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

    @method
    def delete(self, url, **kwargs):
        r"""Sends a DELETE request.

        :param url: URL for the new :class:`Request` object.
        :return: :class:`Response <Response>` object
        :rtype: requests.Response
        """

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

接着再来实现method装饰器，这里有点不同的是，装饰器作用在类的方法上面的，参数有些区别，

def method(f):
    # do something
    def send(self, *args, **kwargs):
        # do something
        return f(self, *args, **kwargs)
    # do something
    return send

send的第一个参数为self，跟类方法对应。

第二、第三个参数兼容了get/post等不同的传参，

return f(self, *args, **kwargs)
#  等价于
return get(self, *args, **kwargs)
# 或
return post(self, *args, **kwargs)

优雅！

至于装饰器里面的do something，可以是记录耗时，打印日志，重试机制，等。