新增登录、登出
app.py中新增：
@app.route(‘/login‘, methods=[‘GET‘, ‘POST‘])
def login():
error = None
if request.method == ‘POST‘:
if request.form.get(‘username‘) != app.config.get(‘USERNAME‘):
error = ‘Invalid username‘
elif request.form.get(‘password‘) != app.config.get(‘PASSWORD‘):
error = ‘Invalid password‘
else:
session[‘login‘] = True
flash(‘You\‘re loginned successfully!‘)
return redirect(url_for(‘show_entries‘))
return render_template(‘login.html‘, error=error)
@app.route(‘/logout‘)
def logout():
session.pop(‘login‘, None)
flash(‘You have logouted successfully‘)
return redirect(url_for(‘show_entries‘))
login.html
{% extends "layout.html" %}
{% block body %}
<h2>Login</h2>
{% if error %}<p class=error><strong>Error:</strong> {{ error }}{% endif %}
<form action="{{ url_for(‘login‘) }}" method=post>
<dl>
<dt>Username:
<dd><input type=text name=username>
<dt>Password:
<dd><input type=password name=password>
<dd><input type=submit value=Login>
</dl>
</form>
{% endblock %}
layout.html
<!doctype html>
<html>
<head>
<title>Flaskr</title>
<link rel=‘stylesheet‘ type=‘text/css‘ href="{{ url_for(‘static‘, filename=‘style.css‘) }}">
</head>
<body>
<div class=‘page‘>
<h1>Flaskr</h1>
<div class=‘metanav‘>
{% if not session.login %}
<a href="{{ url_for(‘login‘) }}">log in</a>
{% else %}
<a href="{{ url_for(‘logout‘) }}">log out</a>
{% endif %}
</div>
{% for message in get_flashed_messages() %}
<div class=‘flash‘>{{ message }}</div>
{% endfor %}
{% block body %}{% endblock %}
</div>
</body>
</html>
原文：https://www.cnblogs.com/holaworld/p/12672763.html