flask书写后台管理程序

使用Flask可以快速、灵活地搭建一个后台管理系统，下面是一个简单的示例：

1. 安装Flask和相关扩展库

pip install Flask
pip install Flask-WTF
pip install Flask-Login
pip install Flask-Migrate

2. 创建Flask应用程序

from flask import Flask
from flask_login import LoginManager
from flask_migrate import Migrate
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config.from_object('config')

db = SQLAlchemy(app)
migrate = Migrate(app, db)
login_manager = LoginManager(app)
login_manager.login_view = 'login'

from app import views, models

3. 创建模型类

from app import db

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), index=True, unique=True)
    password_hash = db.Column(db.String(128))

    def __repr__(self):
        return '<User {}>'.format(self.username)

4. 创建视图函数

from flask import render_template
from flask_login import login_required

@app.route('/')
@login_required
def index():
    return render_template('index.html')

5. 创建模板文件

{% extends "base.html" %}

{% block content %}
  <h1>欢迎来到后台管理系统</h1>
{% endblock %}

6. 创建表单类

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
from wtforms.validators import DataRequired, EqualTo

class LoginForm(FlaskForm):
    username = StringField('用户名', validators=[DataRequired()])
    password = PasswordField('密码', validators=[DataRequired()])
    submit = SubmitField('登录')

7. 创建登录视图函数

from flask import render_template, redirect, url_for, flash
from flask_login import login_user, logout_user, current_user, login_required
from app import app, db, login_manager
from app.forms import LoginForm
from app.models import User

@login_manager.user_loader
def load_user(id):
    return User.query.get(int(id))

@app.route('/login', methods=['GET', 'POST'])
def login():
    if current_user.is_authenticated:
        return redirect(url_for('index'))
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.username.data).first()
        if user is None or not user.check_password(form.password.data):
            flash('用户名或密码错误')
            return redirect(url_for('login'))
        login_user(user, remember=form.remember_me.data)
        return redirect(url_for('index'))
    return render_template('login.html', title='登录', form=form)

8. 创建登出视图函数

from flask_login import logout_user

@app.route('/logout')
@login_required
def logout():
    logout_user()
    return redirect(url_for('login'))

9. 创建配置文件

import os

basedir = os.path.abspath(os.path.dirname(__file__))

class Config(object):
    SECRET_KEY = os.environ.get('SECRET_KEY') or 'hard to guess string'
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or \
        'sqlite:///' + os.path.join(basedir, 'app.db')
    SQLALCHEMY_TRACK_MODIFICATIONS = False

以上是一个简单的Flask后台管理系统的示例，您可以根据自己的需求进行修改和扩展。