阶段总结
这一阵子对flask的学习主要是参考文档和网易云课堂的视频教程，简单了解的项目结构搭建、模型建立、路由、装饰器等使用，虽然都说flask是很轻量级很快的框架，但是毕竟能力尚浅还没有具体感受到其中的重点，但是简单的功能开发已经可以实现了，后期还有包括蓝图、缓存机制、异步等都只能等之后慢慢在项目中摸索了，实验室新任务必须转到sanic去了，所以Flask的学习得先放一阵子了，这里简单总结下，并把网易云课堂里面的案例给大家展示一下
案例
-
项目结构
image.png - 模型(models.py)
models里面主要是模型的建立，用户模型、问答模型和评论模型，重点在于外键和反向关联这一块，模型的迁移以及表更新的代码块都在manage.py内
from exts import db
from datetime import datetime
class User(db.Model):
__tablename__ = 'user'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
telephone = db.Column(db.String(11), nullable=False)
username = db.Column(db.String(50), nullable=False)
password = db.Column(db.String(100), nullable=False)
class Question(db.Model):
__tablename__ = 'question'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
title = db.Column(db.String(50), nullable=False)
content = db.Column(db.Text, nullable=False)
create_time = db.Column(db.DateTime, default=datetime.now)
author_id = db.Column(db.Integer,db.ForeignKey('user.id'))
author = db.relationship('User', backref=db.backref('questions'))
class Comment(db.Model):
__tablename__ = 'comment'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
content = db.Column(db.Text, nullable=False)
question_id = db.Column(db.Integer, db.ForeignKey('question.id'))
create_time = db.Column(db.DateTime, default=datetime.now)
author_id = db.Column(db.Integer, db.ForeignKey('user.id'))
author = db.relationship('User', backref=db.backref('comments'))
question = db.relationship('Question', backref=db.backref('comments'), order_by=create_time.desc())
- 配置(config.py)
配置文件都单独出来，里面主要是数据库连接上的配置,数据库还是使用的mysql数据库，使用pymysql连接
import os
import pymysql
SECRET_KEY = os.urandom(24)
SQLALCHEMY_DATABASE_URI ='mysql+pymysql://root:299521@127.0.0.1:3306/flask_test'
SQLALCHEMY_TRACK_MODIFICATIONS = False
- 扩展包(exts.py)
exts里面对db进行初始化，放置主文件与models文件相互调用产生异常
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
- 包管理(manage.py)
重点是要引入模型和app以及对命令的添加，执行迁移时一定记得父命令(db)
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
from flask_test import app
from exts import db
import pymysql
from models import User, Question
manager = Manager(app)
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)
if __name__ == '__main__':
manager.run()
- 装饰器(decorators.py)
这里涉及到对登录的验证，所以自定义了装饰器，对装饰器不太熟悉的话建议去看看文档
from functools import wraps
from flask import session
from flask import redirect, url_for
def login_required(func):
@wraps(func)
def wrapper(*args, **kwargs):
if session.get('user_id'):
return func(*args, **kwargs)
else:
return redirect(url_for('login'))
return wrapper
- 主文件(flask_test.py)
主要代码块里面重点在于对表单数据的提取，GET、POST请求的差异，其它诸如url_for，模板渲染都相对基础，session的设置和路由参数指定也可以详细看一下
from flask import Flask, render_template, request, session, url_for, redirect
import config
from decorators import login_required
import pymysql
from exts import db
from models import User, Question, Comment
app = Flask(__name__)
app.config.from_object(config)
db.init_app(app)
@app.route('/')
def index():
context = {
'questions': Question.query.order_by('-create_time').all()
}
return render_template('index.html', **context)
@app.route('/detail/<question_id>/')
def detail(question_id):
question_model = Question.query.filter(Question.id == question_id).first()
return render_template('detail.html', question = question_model)
@app.route('/comment/', methods=['POST'])
@login_required
def comment():
content = request.form.get('content')
question_id = request.form.get('question_id')
comment = Comment(content=content)
user_id = session.get('user_id')
user = User.query.filter(User.id==user_id).first()
comment.user = user
question = Question.query.filter(Question.id==question_id).first()
comment.question = question
db.session.add(comment)
db.session.commit()
return redirect(url_for('detail', question_id=question_id))
@app.route('/login/', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
return render_template('login.html')
else:
telephone = request.form.get('telephone')
password = request.form.get('password')
user = User.query.filter(User.telephone == telephone, User.password == password).first()
if user:
session['user_id'] = user.id
session.permanent = True
return redirect(url_for('index'))
else:
return '登录失败'
@app.route('/register/', methods=['GET', 'POST'])
def register():
if request.method == 'GET':
return render_template('register.html')
else:
telephone = request.form.get('telephone')
username = request.form.get('username')
password1 = request.form.get('password1')
password2 = request.form.get('password2')
if User.query.filter(User.telephone == telephone).first():
return '当前号码已注册'
else:
if User.query.filter(User.username == username).first():
return 'username已注册'
else:
if password1 == password2:
user = User(username=username, telephone=telephone, password=password2)
db.session.add(user)
db.session.commit()
return redirect(url_for('login'))
else:
return '密码不符合'
@app.route('/logout/' )
def logout():
session.pop('user_id')
return redirect(url_for('login'))
@app.route('/push_article/', methods=['GET', 'POST'] )
@login_required
def push_article():
if request.method == 'GET':
return render_template('push.html')
else:
title = request.form.get('title')
content = request.form.get('content')
question = Question(title=title, content=content)
user_id = session.get('user_id')
user = User.query.filter(User.id==user_id).first()
question.author = user
db.session.add(question)
db.session.commit()
return redirect(url_for('index'))
@app.context_processor
def has_user():
user_id = session.get('user_id')
if user_id:
user = User.query.filter(User.id == user_id).first()
if user:
return {'user':user}
else:
return {}
else:
return {}
if __name__ == '__main__':
app.run(debug=True)
总结
总体来说，案例很简单，综合考察了之前所总结的所有小模块的功能，最后结合Bootstrap一起做了一个简易博客的小案例，页面其实不用太过在意，重点关注与后台实现，大家不熟悉的话建议尝试一下这个案例
