Flask 知识点小汇总

Flask 知识点小汇总

不知道而信口开河是不明智的、知道了却闭口不讲是没有尽心竭力。 –佚名

请求方法

因为涉及到了跨域所以必须安装包 flask_cors

• HTTP 请求一共有两种第一种 GET,第二种 POST

默认 HTTP methods 是 GET 可以通过 methods 参数设定,GET 请求

from flask import Flask
from flask import request
from flask_cors import CORS
app = Flask(__name__)

@app.route('/login',methods=['GET'])
def login():
    if request.method =='POST':
      return '这是Post请求'
    else:
       return '这是GET请求'

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

• 第二种 POST 请求

from flask import Flask
from flask import request
from flask_cors import CORS
app = Flask(__name__)

@app.route('/login',methods=['GET'])
def login():
    if request.method =='POST':
      return '这是Post请求'
    else:
       return '这是GET请求'

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

• 第三种 GET POST 请求

from flask import Flask
from flask import request
from flask_cors import CORS
app = Flask(__name__)

@app.route('/login',methods=['GET','POST'])
def login():
    if request.method =='POST':
      return '这是Post请求'
    else:
       return '这是GET请求'

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

获取用户发送的数据

• 利用 request 用户发送过来的数据, request.json,request.args

from flask import Flask
from flask import request
from flask_cors import CORS
from flask import jsonify
app = Flask(__name__)

@app.route('/login',methods=['GET','POST'])
def login():
    if request.method =='POST':
        #print (request.data)
        # print(request.headers)
        print(request.json)
        userdata = request.json
        return '这是POST请求'+ userdata['name']
    else:
        #发送数据的类型类似 http://127.0.0.1:5000/v1/user/get?name = hello
         print(request.headers['auth'])
         print("-----------")
         print(request.args['name'])
         print("--------------")
         print(request.args.to_dict()) # 利用to_dict 变成字典
         return '这是GET请求' + request.args['name']

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

获取用户通过 URL 传递过来的数据

from flask import Flask
from flask import request
from flask_cors import CORS
from flask import jsonify
app = Flask(__name__)

@app.route('/login/<q>/<isbn>',methods=['GET'])
def login(q,isbn):
    if request.method =='GET':
         return "用户输入的是"+q +"尾号是"+isbn
    else:
       return '这是GET请求'

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

• 获取用户上传的图片

from flask import Flask
from flask import request
from flask_cors import CORS
from flask import jsonify
app = Flask(__name__)

@app.route('/login',methods=['GET','POST'])
def login():
    if request.method =='POST':
        # 文件对象保存在request.files上，并且通过前端的input标签的name属性来获取
        fp = request.files.get("f1")
        # 保存文件到服务器本地
        fp.save("a.jpg")
        return '保存成功'
    else:
       return '这是GET请求'

if __name__ == "__main__":
    CORS(app,supports_credentials=True)
    app.run()

操作 cookies

• delete_cookie()

• set_cookie()

• cookies.get()

from flask import request
from flask import Flask
from flask import Response
from flask_cors import CORS
from datetime import datetime, timedelta
from flask import make_response
app = Flask(__name__)

#获取cookie
@app.route('/get_cookie/')
def get_cookie():
       name = request.cookies.get('username')
       return  name

#删除cookie
@app.route('/del_cookie/')
def del_cookie():
       resp = make_response('delete_cookie')
       resp.delete_cookie('username')
       return resp

#设置cookie
@app.route('/set_cookie/',methods=['GET'])
def set_cookie():
    resp = make_response('set_cookie')
    resp.set_cookie('username','hahaha', expires=datetime(2026, 4, 19, 14, 0, 0))
    return resp


if __name__ == "__main__":
     CORS(app,supports_credentials=True)
     app.run()

返回格式是 json

from flask import request
from flask import Flask
from flask import Response
from flask_cors import CORS
from datetime import datetime, timedelta
from flask import make_response
from flask import jsonify
from flask import json
app = Flask(__name__)

# 路由

@app.route('/returnjson/',methods=['GET','POST'])

def returnjson2():
    data = {"a":"b"}
    response = make_response(json.dumps(data))
    response.headers["Content-Type"] = "application/json"
    return response


@app.route('/returnjson/',methods=['GET','POST'])

def returnjson():
    data = {"a":"b"}
    response = make_response(jsonify(data))
    #response.headers["Content-Type"] = "application/json" 这句就可以省略了
    return response

if __name__ == "__main__":
     CORS(app,supports_credentials=True)
     app.run()

操作配置文件

• 有的时候我们想获取到或者使用 app.config 里面的配置文件

• 这个时候必须使用 flask 下面的 current_app

from flask import current_app
print(current_app.config['SETTING_PAGE'])