Python網頁設計：Flask使用筆記(一) -基本環境建立

#20190527更新route方法

初始化

建立專案資料夾

mkdir python-flask-app
cd python-flask-app

建立虛擬環境

conda create -n python-flask-app python=3.6
activate python-flask-app

安裝 Flask 模組

 pip install flask

建立main.py

from flask import Flask
app = Flask(__name__)
@app.route('/')
def index():
    return '<h1>Hello, World!</h1>'
if __name__ == "__main__":
    app.run(debug=True,port=8000,threaded=True)
#CMD執行 python main.py
#debug=True時，一修改程式存檔，它就會自動reload
#瀏覽器網址列輸入 localhost:8000(預設port為5000，可調整至其他數字)
#加入thread參數，可以一次處理多個request

修改main.py

from flask import Flask
app = Flask(__name__)
@app.route('/')
def index():
    return '<h1>Hello, World!</h1>'
@app.route('/yanwei')
def yanwei():
    return "<h1>Hello, Yanwei</h1>"
if __name__ == "__main__":
    app.run(debug=True)

再次執行 main.py

前往 http://localhost:5000/yanwei

Hello, Yanwei

產生route的變化

from flask import Flask, jsonify, request
app = Flask(__name__)
#一般
@app.route('/')                        
def index():
    return '<h1>Hello, World!</h1>'
#使用POST和GET方法，可隨意在/home/目錄下，輸入文字名稱進入不同頁面@app.route('/home', methods=['POST', 'GET'], defaults={'name' : 'Default'})                            
#輸入的內容將被轉成字串，使用POST和GET方法，且為動態網址
@app.route('/home/<string:name>', methods=['POST', 'GET'])
def home(name):
    return '<h1>Hello {}, you are on the home page!</h1>'.format(name)
#呈現JSON資料
@app.route('/json')
def json():
    return jsonify({'key' : 'value', 'listkey' : [1,2,3]})
#查詢頁query
@app.route('/query')
def query():
    name = request.args.get('name')
    location = request.args.get('location')
    return '<h1>Hi {}. You are from {}. You are on the query page!</h1>'.format(name, location)
(網址位於/query?name=Yanwei&location=Taiwan)
#透過表格傳送資料，產生動態結果　
@app.route('/theform')
def theform():
    return '''<form method="POST" action="/process">
                  <input type="text" name="name">
                  <input type="text" name="location">
                  <input type="submit" value="Submit">
              </form>'''
@app.route('/process', methods=['POST'])
def process():
    name = request.form['name']
    location = request.form['location']
return '<h1>Hello {}. You are from {}. You have submitted the form successfully!<h1>'.format(name, location)
#傳送JSON資料，使網頁產生變化
@app.route('/processjson', methods=['POST'])
def processjson():
    data = request.get_json()
    name = data['name']
    location = data['location']
    randomlist = data['randomlist']
return jsonify({'result' : 'Success!', 'name' : name, 'location' : location, 'randomkeyinlist' : randomlist[1]})
if __name__ == '__main__':
    app.run(debug=True)