flask配置文件
flask路由系统
@app.route() 装饰器中的参数
如果不明白装饰器 点击这里
methods : 当前 url 地址,允许访问的请求方式
@app.route("/info", methods=["GET", "POST"])
def student_info():
stu_id = int(request.args["id"])
return f"Hello Old boy {stu_id}" # Python3.6的新特性 f"{变量名}"
endpoint : 反向url地址,默认为视图函数名 (url_for)
from flask import url_for
@app.route("/info", methods=["GET", "POST"], endpoint="r_info")
def student_info():
print(url_for("r_info")) # /info
stu_id = int(request.args["id"])
return f"Hello Old boy {stu_id}" # Python3.6的新特性 f"{变量名}"
defaults : 视图函数的参数默认值{"nid":1}
from flask import url_for
@app.route("/info", methods=["GET", "POST"], endpoint="r_info", defaults={"nid": 100})
def student_info(nid):
print(url_for("r_info")) # /info
# stu_id = int(request.args["id"])
print(nid) # 100
return f"Hello Old boy {nid}" # Python3.6的新特性 f"{变量名}"
strict_slashes : url地址结尾符"/"的控制 False : 无论结尾 "/" 是否存在均可以访问 , True : 结尾必须不能是 "/"
# 访问地址 : /info
@app.route("/info", strict_slashes=True)
def student_info():
return "Hello Old boy info"
# 访问地址 : /infos or /infos/
@app.route("/infos", strict_slashes=False)
def student_infos():
return "Hello Old boy infos"
redirect_to : url地址重定向
# 访问地址 : /info 浏览器跳转至 /infos
@app.route("/info", strict_slashes=True, redirect_to="/infos")
def student_info():
return "Hello Old boy info"
@app.route("/infos", strict_slashes=False)
def student_infos():
return "Hello Old boy infos"
subdomain : 子域名前缀 subdomian="DragonFire" 这样写可以得到 DragonFire.oldboyedu.com 前提是app.config["SERVER_NAME"] = "oldboyedu.com"
app.config["SERVER_NAME"] = "oldboy.com"
@app.route("/info",subdomain="DragonFire")
def student_info():
return "Hello Old boy info"
# 访问地址为: DragonFire.oldboy.com/info
关于路由目前就说这么多,之后的课程中会有关于Flask路由系统的源码剖析,再详细说明Flask路由系统的工作原理
动态参数路由:
from flask import url_for
# 访问地址 : http://127.0.0.1:5000/info/1
@app.route("/info/<int:nid>", methods=["GET", "POST"], endpoint="r_info")
def student_info(nid):
print(url_for("r_info",nid=2)) # /info/2
return f"Hello Old boy {nid}" # Python3.6的新特性 f"{变量名}"
就是在url后定义一个参数接收
但是这种动态参数路由,在url_for的时候,一定要将动态参数名+参数值添加进去,否则会抛出参数错误的异常
路由正则:
一般不用,如果有特殊需求,不怕麻烦的话,这个东西还是挺好用的,前提是你的正则玩儿的很6
注意事项以及源码示例：
flask的路由系统比较特殊，是通过装饰器实现的，但是究其本质，还是通过 app.add_url_rute 方法来实现的。
from flask import Flask, request, current_app
import importlib
app = Flask(__name__)
# 导入配置文件
app.config.from_object('settings.DevConfig')
# flask路由系统
@app.route('/')
def hello_world():
return 'Hello World!'
路由源码以及其分析
# 以 @app.route('/index', endpoint='index', methods=['GET']) 为例
# 函数本质是是个闭包函数
def route(self, rule, **options):
# self 表示的app对象的实例
# rule 表示路由 rule='/index'
# **options 是其他参数 这里 endpoint='index', methods=['GET']
def decorator(f):
# 这里是获取 endpoint的值，如果不存在则为None
endpoint = options.pop("endpoint", None)
# 本质上是 执行 app.add_url_rule('/index',....)
self.add_url_rule(rule, endpoint, f, **options)
return f
return decorator
"""
第一步 执行route 后返回 decorator
第二步 执行@decorator -->decorator(index)
"""
@app.route('/index', endpoint='index', methods=['GET'])
# 参数endpoint不写 默认为函数名,用户反向生成url
def index():
print(current_app.config['DB'])
return "xxx"
def login():
return 'login'
# 这是另外一种路由方式，类似于django中的path('',views.....)
app.add_url_rule('/login', 'n2',login,methods=['GET', 'POST'])
if __name__ == '__main__':
app.run()
def _endpoint_from_view_func(view_func):
"""
Internal helper that returns the default endpoint for a given
function. This always is the function name.
"""
assert view_func is not None, "expected view func if endpoint is not provided."
# 如果 endpoint=None的时候，返回的是 默认的endpoint view_func的名字
return view_func.__name__
CBV简单实现
from flask import Flask, request, current_app,views
import importlib
app = Flask(__name__)
app.config.from_object('settings.DevConfig')
# 装饰器
def auth(func):
def inner(*args,**kwargs):
result = func(*args,**kwargs)
return result
return inner
class IndexView(views.MethodView):
methods = ['GET','POST']
decorators =[auth,]
def get(self):
return 'index.get'
def post(self):
return 'index.post'
app.add_url_rule('/index',view_func=IndexView.as_view(name='index')) # name=endpoint
if __name__ == '__main__':
app.run()
源码分析
class MethodView(with_metaclass(MethodViewType, View)):
"""A class-based view that dispatches request methods to the corresponding
class methods. For example, if you implement a ``get`` method, it will be
used to handle ``GET`` requests. ::
class CounterAPI(MethodView):
def get(self):
return session.get('counter', 0)
def post(self):
session['counter'] = session.get('counter', 0) + 1
return 'OK'
app.add_url_rule('/counter', view_func=CounterAPI.as_view('counter'))
"""
# 类似于django中的dispatch，视图类中分发不同请求说对应的方法
def dispatch_request(self, *args, **kwargs):
meth = getattr(self, request.method.lower(), None)
# If the request method is HEAD and we don't have a handler for it
# retry with GET.
if meth is None and request.method == "HEAD":
meth = getattr(self, "get", None)
assert meth is not None, "Unimplemented method %r" % request.method
return meth(*args, **kwargs)
# 如果是get请求，返回的是 get(*args,**kwargs)
host文件路径(修改本地DNS对应关系)
windows：C:\Windows\System32\drivers\etc\hosts
mac：/etc/hosts
转载于:https://www.cnblogs.com/qianzhengkai/p/11380601.html
