封装requests库统一接口请求

新建package common.  封装统一请求

 

import requests


class SendRequest:
    '''
    调用requests库的 session()方法. 该方法返回一个Session()类对象. 该类对象用于 上下文管理. 该类中有request()方法等
    这里其实可以直接调用类对象Session(). 因为requests.session() 此方法自1.0.0版起已弃用，仅保留向后兼容性。
    '''
    s = requests.Session()   # 实例化会话一个会话对象, 会话对象让你能够跨请求保持某些参数。它也会在同一个 Session 实例发出的所有请求之间保持 cookie

    def send_one_request(self, method, url, **kwargs):   # 其实很多接口需要先登录,然后保存cookie. 测试用例可以前置登录.再测试其他接口
        try:
            res = SendRequest.s.request(method, url, **kwargs) 

        except BaseException as e:
            print("接口请求失败")
            raise e
    else:
        print("接口请求成功")
        return res

 

原理:

# requests模块常用的方法:
requests.get()
requests.post()
requests.put()
requests.delete()
requests.reuqest()
requests.session()
# requests模块常用方法的底层原理
# requests.get()方法
    def get(url, params=None, **kwargs):
        return request("get", url, params=params, **kwargs)
# requests.post()
    def post(url, data=None, json=None, **kwargs):
        return request("post", url, data=data, json=json, **kwargs)
# requests.put()
    def put(url, data=None, **kwargs):
        return request("put", url, data=data, **kwargs)
# requests.delete()
    def delete(url, **kwargs):
        return request("delete", url, **kwargs)   
# 综上可以看出:  requests模块中的get,post,delete,put方法底层调用的是requests模块的request()方法                                                             
# requests.request()
    def request(method, url, **kwargs):
        with sessions.Session() as session:  # 创建一个session对象
            # 可以看出: requests模块中request方法底层调用的是Session对象的reuqest()方法
            return session.request(method=method, url=url, **kwargs) 
# requests.session()
    def session(): # 会话, web项目从登录和退出就是一个会话.
        return Session()

由上可以看出:

requests模块中的get,post,delete,put方法底层统一调用的是requests模块的request方法,

而requests模块的request方法底层调用的是sessions.py 模块中的 Session()类对象中的reuqest方法

 

#session对象的request方法:
def request(
    self,
    method,    # 请求方法
    url,       # 请求路径
    params=None,  # get请求传参
    data=None,    # post或put请求传参
    headers=None, # 请求头
    cookies=None, # cookie信息
    files=None,   # post请求传参(文件上传multipart/form-data)
    auth=None,    # 鉴权
    timeout=None, # 超时处理
    allow_redirects=True, # 是否允许重定向
    proxies=None, # 代理
    hooks=None,   # 钩子
    stream=None,  # 文件下载
    verify=None,  # 证书验证
    cert=None,    # CA证书
    json=None,    # post请求传参(application/json)
): 

 

res.text  #返回文本格式
res.content # 返回bytes类型数据据
res.json() # 返回json数据
res.status_code # 返回状态码
res.reason  #返回状态信息
res.cookies # 返回cookie信息
res.headers # 返回响应头
res.request.???   #返回请求的信息和数据 

 

===================================================================================

s = requests.session() 调用说明  [注: 1.0.0起已启用. 仅保留向后兼容性, 建议使用 s = requests.Session() ]

===================================================================================

def session():
    """
    Returns a :class:`Session` for context-management.

    .. deprecated:: 1.0.0

        This method has been deprecated since version 1.0.0 and is only kept for
        backwards compatibility. New code should use :class:`~requests.sessions.Session`
        to create a session. This may be removed at a future date.

    :rtype: Session
    """
    return Session()

 

==============================================================================================================

requests.get() /request.post() 等 底层调用说明 [调用 requests库的api.py模块中get()/post() 等方法, 该方法返回的是api.py模块中的request()方法. ]

==============================================================================================================

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)

[api.py模块中的request()方法返回的是 sessions.py模块中的Session()类对象中的request()方法]

from . import sessions


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

    :param method: method for the new :class:`Request` object: ``GET``, ``OPTIONS``, ``HEAD``, ``POST``, ``PUT``, ``PATCH``, or ``DELETE``.
    :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')
      >>> req
      <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)

========================================================================================================================

sessions.Session().request()调用说明:  [ 调用sessions.py模块中的Session()对象的 request()方法. 且执行后会自动执行其中的__exit__()方法,关掉session  ]

========================================================================================================================

class Session(SessionRedirectMixin):
    """A Requests session.

    Provides cookie persistence, connection-pooling, and configuration.

    Basic Usage::

      >>> import requests
      >>> s = requests.Session()
      >>> s.get('https://httpbin.org/get')
      <Response [200]>

    Or as a context manager::

      >>> with requests.Session() as s:
      ...     s.get('https://httpbin.org/get')
      <Response [200]>
    """

    __attrs__ = [
        "headers",
        "cookies",
        "auth",
        "proxies",
        "hooks",
        "params",
        "verify",
        "cert",
        "adapters",
        "stream",
        "trust_env",
        "max_redirects",
    ]

    def __init__(self):

        #: A case-insensitive dictionary of headers to be sent on each
        #: :class:`Request <Request>` sent from this
        #: :class:`Session <Session>`.
        self.headers = default_headers()

        #: Default Authentication tuple or object to attach to
        #: :class:`Request <Request>`.
        self.auth = None

        #: Dictionary mapping protocol or protocol and host to the URL of the proxy
        #: (e.g. {'http': 'foo.bar:3128', 'http://host.name': 'foo.bar:4012'}) to
        #: be used on each :class:`Request <Request>`.
        self.proxies = {}

        #: Event-handling hooks.
        self.hooks = default_hooks()

        #: Dictionary of querystring data to attach to each
        #: :class:`Request <Request>`. The dictionary values may be lists for
        #: representing multivalued query parameters.
        self.params = {}

        #: Stream response content default.
        self.stream = False

        #: SSL Verification default.
        #: Defaults to `True`, requiring requests to verify the TLS certificate at the
        #: remote end.
        #: If verify is set to `False`, requests will accept any TLS certificate
        #: presented by the server, and will ignore hostname mismatches and/or
        #: expired certificates, which will make your application vulnerable to
        #: man-in-the-middle (MitM) attacks.
        #: Only set this to `False` for testing.
        self.verify = True

        #: SSL client certificate default, if String, path to ssl client
        #: cert file (.pem). If Tuple, ('cert', 'key') pair.
        self.cert = None

        #: Maximum number of redirects allowed. If the request exceeds this
        #: limit, a :class:`TooManyRedirects` exception is raised.
        #: This defaults to requests.models.DEFAULT_REDIRECT_LIMIT, which is
        #: 30.
        self.max_redirects = DEFAULT_REDIRECT_LIMIT

        #: Trust environment settings for proxy configuration, default
        #: authentication and similar.
        self.trust_env = True

        #: A CookieJar containing all currently outstanding cookies set on this
        #: session. By default it is a
        #: :class:`RequestsCookieJar <requests.cookies.RequestsCookieJar>`, but
        #: may be any other ``cookielib.CookieJar`` compatible object.
        self.cookies = cookiejar_from_dict({})

        # Default connection adapters.
        self.adapters = OrderedDict()
        self.mount("https://", HTTPAdapter())
        self.mount("http://", HTTPAdapter())

    def __enter__(self):
        return self

    def __exit__(self, *args):
        self.close()

    def prepare_request(self, request):
        """Constructs a :class:`PreparedRequest <PreparedRequest>` for
        transmission and returns it. The :class:`PreparedRequest` has settings
        merged from the :class:`Request <Request>` instance and those of the
        :class:`Session`.

        :param request: :class:`Request` instance to prepare with this
            session's settings.
        :rtype: requests.PreparedRequest
        """
        cookies = request.cookies or {}

        # Bootstrap CookieJar.
        if not isinstance(cookies, cookielib.CookieJar):
            cookies = cookiejar_from_dict(cookies)

        # Merge with session cookies
        merged_cookies = merge_cookies(
            merge_cookies(RequestsCookieJar(), self.cookies), cookies
        )

        # Set environment's basic authentication if not explicitly set.
        auth = request.auth
        if self.trust_env and not auth and not self.auth:
            auth = get_netrc_auth(request.url)

        p = PreparedRequest()
        p.prepare(
            method=request.method.upper(),
            url=request.url,
            files=request.files,
            data=request.data,
            json=request.json,
            headers=merge_setting(
                request.headers, self.headers, dict_class=CaseInsensitiveDict
            ),
            params=merge_setting(request.params, self.params),
            auth=merge_setting(auth, self.auth),
            cookies=merged_cookies,
            hooks=merge_hooks(request.hooks, self.hooks),
        )
        return p

    def request(
        self,
        method,
        url,
        params=None,
        data=None,
        headers=None,
        cookies=None,
        files=None,
        auth=None,
        timeout=None,
        allow_redirects=True,
        proxies=None,
        hooks=None,
        stream=None,
        verify=None,
        cert=None,
        json=None,
    ):
        """Constructs a :class:`Request <Request>`, prepares it and sends it.
        Returns :class:`Response <Response>` object.

        :param method: method for the new :class:`Request` object.
        :param url: URL for the new :class:`Request` object.
        :param params: (optional) Dictionary or bytes to be sent 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) json 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 ``'filename': file-like-objects``
            for multipart encoding upload.
        :param auth: (optional) Auth tuple or callable to enable
            Basic/Digest/Custom HTTP Auth.
        :param timeout: (optional) How long 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) Set to True by default.
        :type allow_redirects: bool
        :param proxies: (optional) Dictionary mapping protocol or protocol and
            hostname to the URL of the proxy.
        :param stream: (optional) whether to immediately download the response
            content. Defaults to ``False``.
        :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``. When set to
            ``False``, requests will accept any TLS certificate presented by
            the server, and will ignore hostname mismatches and/or expired
            certificates, which will make your application vulnerable to
            man-in-the-middle (MitM) attacks. Setting verify to ``False``
            may be useful during local development or testing.
        :param cert: (optional) if String, path to ssl client cert file (.pem).
            If Tuple, ('cert', 'key') pair.
        :rtype: requests.Response
        """
        # Create the Request.
        req = Request(
            method=method.upper(),
            url=url,
            headers=headers,
            files=files,
            data=data or {},
            json=json,
            params=params or {},
            auth=auth,
            cookies=cookies,
            hooks=hooks,
        )
        prep = self.prepare_request(req)

        proxies = proxies or {}

        settings = self.merge_environment_settings(
            prep.url, proxies, stream, verify, cert
        )

        # Send the request.
        send_kwargs = {
            "timeout": timeout,
            "allow_redirects": allow_redirects,
        }
        send_kwargs.update(settings)
        resp = self.send(prep, **send_kwargs)

        return resp

    def get(self, url, **kwargs):
        r"""Sends a GET request. Returns :class:`Response` object.

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

        kwargs.setdefault("allow_redirects", True)
        return self.request("GET", url, **kwargs)

    def options(self, url, **kwargs):
        r"""Sends a OPTIONS request. Returns :class:`Response` object.

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

        kwargs.setdefault("allow_redirects", True)
        return self.request("OPTIONS", url, **kwargs)

    def head(self, url, **kwargs):
        r"""Sends a HEAD request. Returns :class:`Response` object.

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

        kwargs.setdefault("allow_redirects", False)
        return self.request("HEAD", url, **kwargs)

    def post(self, url, data=None, json=None, **kwargs):
        r"""Sends a POST request. Returns :class:`Response` object.

        :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 to send in the body of the :class:`Request`.
        :param \*\*kwargs: Optional arguments that ``request`` takes.
        :rtype: requests.Response
        """

        return self.request("POST", url, data=data, json=json, **kwargs)

    def put(self, url, data=None, **kwargs):
        r"""Sends a PUT request. Returns :class:`Response` object.

        :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 \*\*kwargs: Optional arguments that ``request`` takes.
        :rtype: requests.Response
        """

        return self.request("PUT", url, data=data, **kwargs)

    def patch(self, url, data=None, **kwargs):
        r"""Sends a PATCH request. Returns :class:`Response` object.

        :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 \*\*kwargs: Optional arguments that ``request`` takes.
        :rtype: requests.Response
        """

        return self.request("PATCH", url, data=data, **kwargs)

    def delete(self, url, **kwargs):
        r"""Sends a DELETE request. Returns :class:`Response` object.

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

        return self.request("DELETE", url, **kwargs)

    def send(self, request, **kwargs):
        """Send a given PreparedRequest.

        :rtype: requests.Response
        """
        # Set defaults that the hooks can utilize to ensure they always have
        # the correct parameters to reproduce the previous request.
        kwargs.setdefault("stream", self.stream)
        kwargs.setdefault("verify", self.verify)
        kwargs.setdefault("cert", self.cert)
        if "proxies" not in kwargs:
            kwargs["proxies"] = resolve_proxies(request, self.proxies, self.trust_env)

        # It's possible that users might accidentally send a Request object.
        # Guard against that specific failure case.
        if isinstance(request, Request):
            raise ValueError("You can only send PreparedRequests.")

        # Set up variables needed for resolve_redirects and dispatching of hooks
        allow_redirects = kwargs.pop("allow_redirects", True)
        stream = kwargs.get("stream")
        hooks = request.hooks

        # Get the appropriate adapter to use
        adapter = self.get_adapter(url=request.url)

        # Start time (approximately) of the request
        start = preferred_clock()

        # Send the request
        r = adapter.send(request, **kwargs)

        # Total elapsed time of the request (approximately)
        elapsed = preferred_clock() - start
        r.elapsed = timedelta(seconds=elapsed)

        # Response manipulation hooks
        r = dispatch_hook("response", hooks, r, **kwargs)

        # Persist cookies
        if r.history:

            # If the hooks create history then we want those cookies too
            for resp in r.history:
                extract_cookies_to_jar(self.cookies, resp.request, resp.raw)

        extract_cookies_to_jar(self.cookies, request, r.raw)

        # Resolve redirects if allowed.
        if allow_redirects:
            # Redirect resolving generator.
            gen = self.resolve_redirects(r, request, **kwargs)
            history = [resp for resp in gen]
        else:
            history = []

        # Shuffle things around if there's history.
        if history:
            # Insert the first (original) request at the start
            history.insert(0, r)
            # Get the last request made
            r = history.pop()
            r.history = history

        # If redirects aren't being followed, store the response on the Request for Response.next().
        if not allow_redirects:
            try:
                r._next = next(
                    self.resolve_redirects(r, request, yield_requests=True, **kwargs)
                )
            except StopIteration:
                pass

        if not stream:
            r.content

        return r

    def merge_environment_settings(self, url, proxies, stream, verify, cert):
        """
        Check the environment and merge it with some settings.

        :rtype: dict
        """
        # Gather clues from the surrounding environment.
        if self.trust_env:
            # Set environment's proxies.
            no_proxy = proxies.get("no_proxy") if proxies is not None else None
            env_proxies = get_environ_proxies(url, no_proxy=no_proxy)
            for (k, v) in env_proxies.items():
                proxies.setdefault(k, v)

            # Look for requests environment configuration
            # and be compatible with cURL.
            if verify is True or verify is None:
                verify = (
                    os.environ.get("REQUESTS_CA_BUNDLE")
                    or os.environ.get("CURL_CA_BUNDLE")
                    or verify
                )

        # Merge all the kwargs.
        proxies = merge_setting(proxies, self.proxies)
        stream = merge_setting(stream, self.stream)
        verify = merge_setting(verify, self.verify)
        cert = merge_setting(cert, self.cert)

        return {"proxies": proxies, "stream": stream, "verify": verify, "cert": cert}

    def get_adapter(self, url):
        """
        Returns the appropriate connection adapter for the given URL.

        :rtype: requests.adapters.BaseAdapter
        """
        for (prefix, adapter) in self.adapters.items():

            if url.lower().startswith(prefix.lower()):
                return adapter

        # Nothing matches :-/
        raise InvalidSchema(f"No connection adapters were found for {url!r}")

    def close(self):
        """Closes all adapters and as such the session"""
        for v in self.adapters.values():
            v.close()

    def mount(self, prefix, adapter):
        """Registers a connection adapter to a prefix.

        Adapters are sorted in descending order by prefix length.
        """
        self.adapters[prefix] = adapter
        keys_to_move = [k for k in self.adapters if len(k) < len(prefix)]

        for key in keys_to_move:
            self.adapters[key] = self.adapters.pop(key)

    def __getstate__(self):
        state = {attr: getattr(self, attr, None) for attr in self.__attrs__}
        return state

    def __setstate__(self, state):
        for attr, value in state.items():
            setattr(self, attr, value)