#类似于django wsgiref
from werkzeug.wrappers import Request, Response
from werkzeug.serving import run_simple

#实例一
def run(environ,start_response):
    return [b"asdfasdf"]

if __name__ == ‘__main__‘:
    run_simple(‘localhost‘, 4000, run)  #请求进来了会加括号执行第三个参数 如果是对象的话 会触发__call__

    

示例二：
from werkzeug.wrappers import Request, Response

@Request.application
def hello(request):
	return Response(‘Hello World!‘)

if __name__ == ‘__main__‘:
    from werkzeug.serving import run_simple
    run_simple(‘localhost‘, 4000, hello)		    
		

from flask import Flask
app = Flask(__name__)

@app.route(‘/index‘)
def index():
    return "Hello World"

if __name__ == ‘__main__‘:  #防止被导入时候也被运行
    app.run()

from flask import Flask,render_template,request,redirect,session
app = Flask(__name__,template_folder="templates")

@app.route(‘/login‘,methods=["GET","POST"]) #允许提交的method  默认是Get
def login():
    if request.method == ‘GET‘:
        return render_template(‘login.html‘)
    user = request.form.get(‘user‘)     #这个request必须导才能使用（上下文管理）form 是post 数据 
    pwd = request.form.get(‘pwd‘)     #get 数据在request.args 
    if user == ‘oldboy‘ and pwd == ‘666‘:
        session[‘user‘] = user
        return redirect(‘/index‘)  #重跳转
    return render_template(‘login.html‘,error=‘用户名或密码错误‘)  #后端可以拿到这个error ｛｛error｝｝
    # return render_template(‘login.html‘,**{"error":‘用户名或密码错误‘})

@app.route(‘/index‘)
def index():
    user = session.get(‘user‘)
    if not user:
        return redirect(‘/login‘)
    return render_template(‘index.html‘)

if __name__ == ‘__main__‘:
    app.run()