Flask之请求与响应

一、请求

Flask中的请求只需要导入以下内容即可：

from flask import request

request对象中有以下部分参数：

"""
request.data
request.form
request.query_string
request.method
request.args
request.values
request.cookies
request.headers
request.path
request.full_path
request.script_root
request.url
request.base_url
request.url_root
request.host_url
request.host
request.files
...
"""

　　如果查看request对象中存在的方法，可以去flask.wrappers.Request类下进行查看，而Request类继承了werkzeug.wrappers.Request，所以你可以去这两个类下查看对应的方法和属性。

大部分的方法是在下面这几个个类中，查看用法可以看这几个类中对方法的一些说明：

##werkzeug\wrappers\request.py

from .accept import AcceptMixin
from .auth import AuthorizationMixin
from .base_request import BaseRequest
from .common_descriptors import CommonRequestDescriptorsMixin
from .cors import CORSRequestMixin
from .etag import ETagRequestMixin
from .user_agent import UserAgentMixin


class Request(
    BaseRequest,
    AcceptMixin,
    ETagRequestMixin,
    UserAgentMixin,
    AuthorizationMixin,
    CORSRequestMixin,
    CommonRequestDescriptorsMixin,
):
    """Full featured request object implementing the following mixins:

    -   :class:`AcceptMixin` for accept header parsing
    -   :class:`ETagRequestMixin` for etag and cache control handling
    -   :class:`UserAgentMixin` for user agent introspection
    -   :class:`AuthorizationMixin` for http auth handling
    -   :class:`~werkzeug.wrappers.cors.CORSRequestMixin` for Cross
        Origin Resource Sharing headers
    -   :class:`CommonRequestDescriptorsMixin` for common headers

    """

二、响应

Flask中的响应只需要导入以下内容即可：

from flask import redirect
from flask import render_template
from flask import make_response

上面的三个方法都可以进行相应。

　　其中make_response类的对象是flask.wrappers.Response类型，Response继承的是werkzeug.wrappers.Response类，所以如果看响应中有什么属性和方法可以去werkzeug.wrappers.Response类中查看：

##werkzeug\wrappers\response.py

class Response(
    BaseResponse,
    ETagResponseMixin,
    WWWAuthenticateMixin,
    CORSResponseMixin,
    ResponseStreamMixin,
    CommonResponseDescriptorsMixin,
):
    """Full featured response object implementing the following mixins:

    -   :class:`ETagResponseMixin` for etag and cache control handling
    -   :class:`WWWAuthenticateMixin` for HTTP authentication support
    -   :class:`~werkzeug.wrappers.cors.CORSResponseMixin` for Cross
        Origin Resource Sharing headers
    -   :class:`ResponseStreamMixin` to add support for the ``stream``
        property
    -   :class:`CommonResponseDescriptorsMixin` for various HTTP
        descriptors
    """

例如，在BaseResponse类中存在

class BaseResponse(object):
        """
           ...
        """
    @property
    def status(self):
        """The HTTP status code as a string."""
        return self._status
    def set_cookie(
        self,
        key,
        value="",
        max_age=None,
        expires=None,
        path="/",
        domain=None,
        secure=False,
        httponly=False,
        samesite=None,
    ):
        """Sets a cookie. The parameters are the same as in the cookie `Morsel`
        object in the Python standard library but it accepts unicode data, too.

        A warning is raised if the size of the cookie header exceeds
        :attr:`max_cookie_size`, but the header will still be set.

        :param key: the key (name) of the cookie to be set.
        :param value: the value of the cookie.
        :param max_age: should be a number of seconds, or `None` (default) if
                        the cookie should last only as long as the client's
                        browser session.
        :param expires: should be a `datetime` object or UNIX timestamp.
        :param path: limits the cookie to a given path, per default it will
                     span the whole domain.
        :param domain: if you want to set a cross-domain cookie.  For example,
                       ``domain=".example.com"`` will set a cookie that is
                       readable by the domain ``www.example.com``,
                       ``foo.example.com`` etc.  Otherwise, a cookie will only
                       be readable by the domain that set it.
        :param secure: If `True`, the cookie will only be available via HTTPS
        :param httponly: disallow JavaScript to access the cookie.  This is an
                         extension to the cookie standard and probably not
                         supported by all browsers.
        :param samesite: Limits the scope of the cookie such that it will only
                         be attached to requests if those requests are
                         "same-site".
        """
        self.headers.add(
            "Set-Cookie",
            dump_cookie(
                key,
                value=value,
                max_age=max_age,
                expires=expires,
                path=path,
                domain=domain,
                secure=secure,
                httponly=httponly,
                charset=self.charset,
                max_size=self.max_cookie_size,
                samesite=samesite,
            ),
        )

    def delete_cookie(self, key, path="/", domain=None):
        """Delete a cookie.  Fails silently if key doesn't exist.

        :param key: the key (name) of the cookie to be deleted.
        :param path: if the cookie that should be deleted was limited to a
                     path, the path has to be defined here.
        :param domain: if the cookie that should be deleted was limited to a
                       domain, that domain has to be defined here.
        """
        self.set_cookie(key, expires=0, max_age=0, path=path, domain=domain)

...        
    

make_response类的对象就可以调用status()、set_cookie()等方法。

response = make_response(render_template('index.html'))
response.set_cookie('k1', 'v1')