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Flask 框架
$ pip install flask
写一个 app.py
,解决 3 个 URL,别离是:
GET /
:首页,返回Home
;GET /signin
:登录页,显示登录表单;POST /signin
:解决登录表单,显示登录后果。
from flask import Flask
from flask import request
app = Flask(__name__)
@app.route('/', methods=['GET', 'POST'])
def home():
return '<h1>Home</h1>'
@app.route('/signin', methods=['GET'])
def signin_form():
return '''<form action="/signin"method="post">
<p><input name="username"></p>
<p><input name="password" type="password"></p>
<p><button type="submit">Sign In</button></p>
</form>'''@app.route('/signin', methods=['POST'])
def signin():
if request.form['username']=='admin' and request.form['password']=='password':
return '<h3>Hello, admin!</h3>'
return '<h3>Bad username or password.</h3>'
if __name__ == '__main__':
app.run()
应用模板
Flask 默认反对的模板是 jinja2,所以咱们先装置 jinja2:
$ pip install jinja2
批改 app.py
:
# app.py
from flask import Flask, request, render_template
app = Flask(__name__)
@app.route('/', methods=['GET', 'POST'])
def home():
return render_template('home.html')
@app.route('/signin', methods=['GET'])
def signin_form():
return render_template('form.html')
@app.route('/signin', methods=['POST'])
def signin():
username = request.form['username']
password = request.form['password']
if username=='admin' and password=='password':
return render_template('signin-ok.html', username=username)
return render_template('form.html', message='Bad username or password', username=username)
if __name__ == '__main__':
app.run()
减少模板文件:
# templates/form.html
<html>
<head>
<title>Please Sign In</title>
</head>
<body>
{% if message %}
<p style="color:red">{{message}}</p>
{% endif %}
<form action="/signin" method="post">
<legend>Please sign in:</legend>
<p><input name="username" placeholder="Username" value="{{username}}"></p>
<p><input name="password" placeholder="Password" type="password"></p>
<p><button type="submit">Sign In</button></p>
</form>
</body>
</html>
# templates/signin-ok.html
<html>
<head>
<title>Welcome, {{username}}</title>
</head>
<body>
<p>Welcome, {{username}}!</p>
</body>
</html>
运行:
$ python app.py
* Running on http://127.0.0.1:5000/
除了 Flask,常见的 Python Web 框架还有:
- Django:全能型 Web 框架;
- web.py:一个玲珑的 Web 框架;
- Bottle:和 Flask 相似的 Web 框架;
- Tornado:Facebook 的开源异步 Web 框架。
正文完