【代码】Flask+Web开发：基于Python的Web应用开发实战
第2章 程序的基本结构
# encoding=utf-8
from flask import Flask, request, redirect, make_response
from flask_script import Manager
app = Flask(__name__)
# 添加命令行解析功能
manager = Manager(app)
@app.route('/')
def index():
# request object
user_agent = request.headers.get('User-Agent')
return 'hello world!
\r\nYour browser is {}
'.format(user_agent)
# return response, status code
# return 'bad request
',400
# redirect
# return redirect('http://www.baidu.com')
# make response
# response = make_response('This document carries a cookie!
')
# response.set_cookie('answer', '42')
# return response
@app.route('/user/')
def user(name):
return 'hello, {}'.format(name)
@app.route('/user/')
def get_user(id):
user = load_user(id)
if not user:
abort(404)
return 'hello, {}
'.format(user.name)
if __name__ == '__main__':
# app.run(debug=True)
manager.run()
2.6 flask扩展
学到了扩展，Flask-Script别说使用，安装先喝了一壶
python2下 flask-script的情况
先看看书中做法：
安装方式
(venv) $ pip install flask-script
导入方式：
示例 2-3 hello.py：使用 Flask-Script
from flask.ext.script import Manager
环境：python 2.7.6，flask 1.0.2，所以应该不是版本的冲突吧？
报错：ImportError: No module named ext.script
更换导入方式：from flask_script import Manager
依然报错ImportError
deactivate 退出虚拟环境再source venv/bin/activate进入，然并卵
看到一贴：
no module named flask.ext.moment
在虚拟环境（取名：venv）下继续安装：
pip install Flask-Script（显示：Requirement already satisfied）
pip install Flask-Moment
依然报错：ImportError: No module named ext.script
更换导入方式：from flask_script import Manager
于是成功了吧？：
usage: hello.py [-?] {shell,runserver} ...
positional arguments:
{shell,runserver}
shell Runs a Python shell inside Flask application context.
runserver Runs the Flask development server i.e. app.run()
optional arguments:
-?, --help show this help message and exit
python3下 flask-script的情况
后来使用python3的venv安装了虚拟环境（取名：py3）在py3环境下，导入报错，以上方法均不起作用，可见虚拟环境（py3）不被支持。。。
用python2的virtualenv安装虚拟环境（取名：py），在py环境下，运行python hello.py报错，运行python3 hello.py成功，显示：usage: hello.py [-?] {shell,runserver} …
不在虚拟环境py/py3下，运行python/python2/python3 hello.py均成功，所以说是虚拟环境的锅么。。。。。。
python3的安装，然并卵
默默去安装了3.6。。。Ubuntu怎样安装Python3.6，半路get到新技能apt-fast）
因为安装好了py3.6，于是在新建文件夹使拥venv开启虚拟环境，参考：关于Python3中venv虚拟环境
然而运行python3 -m venv .
报错：apt-get install python3-venv
于是安装，又报错：Unable to locate package python3-venv
运行sudo apt-get install python3.6-venv
又报错：python3.6-venv : Depends: python-pip-whl (>= 8.1.0-2) but 1.5.4-1ubuntu4 is
参考这里python3.6 部署后，又采用几种方法升级pip失败。。。。。。
最终把3.4的优先级改回去，在3.4下使用venv开启虚拟环境
那就先用着吧。。。。。
python虚拟环境配置pyenu在不同python版本之间轻松切换，同时参考pyenv-virtualenv插件虚拟出同一版本的python但是不同依赖库版本的开发环境。
ubuntu下环境配置目录/ect/bash.bashrc
第3章 模板
# encoding=utf-8
from flask import Flask, request, redirect, make_response
from flask import render_template
from flask_script import Manager
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from datetime import datetime
# 初始化
app = Flask(__name__)
bootstrap = Bootstrap(app)
moment = Moment(app)
# 添加命令行解析功能
# manager = Manager(app)
@app.route('/')
def index():
return render_template('index.html', current_time=datetime.utcnow())
@app.route('/user/')
def user(name):
return render_template('user.html', name = name)
@app.errorhandler(404)
def page_not_found(e):
return render_template('404.html'), 404
@app.errorhandler(500)
def internal_server_error(e):
return render_template('500.html'), 500
if __name__ == '__main__':
app.run(debug=True)
# manager.run()
3.5 静态文件
书中两句：
示例 3-10 templates/base.html：定义收藏夹图标
{% block head %}
{{ super() }}
{% endblock %}
flask文档：
添加一个页面图标只有一句
只要templates目录下的某.html文件有：{% extends “base.html” %}
其对应页面即可在标签和收藏夹中显示图标
第4章 web表单
# encoding=utf-8
from flask import Flask, request, redirect, make_response
from flask import render_template, session, url_for, flash
from flask_script import Manager
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from datetime import datetime
# 定义表单类
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import Required
class NameForm(FlaskForm):
name = StringField('what\'s your name?', validators=[Required()])
submit = SubmitField('Submit')
# 初始化
app = Flask(__name__)
bootstrap = Bootstrap(app)
moment = Moment(app)
app.config['SECRET_KEY'] = 'hard to guess string'
# 添加命令行解析功能
# manager = Manager(app)
@app.route('/', methods=['GET', 'POST'])
def index():
# name = None
form = NameForm()
if form.validate_on_submit():
old_name = session.get('name')
if old_name is not None and old_name != form.name.data:
flash('Looks like you have changed your name')
session['name'] = form.name.data
return redirect(url_for('index'))
return render_template('index.html', form=form, name=session.get('name'))
@app.route('/user/')
def user(name):
return render_template('user.html', name = name)
@app.errorhandler(404)
def page_not_found(e):
return render_template('404.html'), 404
@app.errorhandler(500)
def internal_server_error(e):
return render_template('500.html'), 500
if __name__ == '__main__':
app.run(debug=True)
# manager.run()
4.4 在视图函数中处理表单
发现注释不掉%{{ block content }}%，但可以注释掉普通html内容
在jinja2中注释是 {# #}
第5章
# encoding=utf-8
from flask import Flask, request, redirect, make_response
from flask import render_template, session, url_for, flash
from flask_script import Manager, Shell
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate, MigrateCommand
from datetime import datetime
import os
# 定义表单类
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import Required
class NameForm(FlaskForm):
name = StringField('what\'s your name?', validators=[Required()])
submit = SubmitField('Submit')
# 初始化
# 配置数据库
basedir = os.path.abspath(os.path.dirname(__file__))
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] =\
'sqlite:///' + os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
db = SQLAlchemy(app)
bootstrap = Bootstrap(app)
moment = Moment(app)
app.config['SECRET_KEY'] = 'hard to guess string'
# 添加命令行解析功能
manager = Manager(app)
# 为 shell 命令添加一个上下文
def make_shell_context():
return dict(app=app, db=db, User=User, Role=Role)
manager.add_command("shell", Shell(make_context=make_shell_context))
# 配置 Flask-Migrate
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)
# 定义 Role 和 User 模型
class Role(db.Model):
__tablename__ = 'roles'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), unique=True)
users = db.relationship('User', backref='role', lazy='dynamic')
def __repr__(self):
return '' % self.name
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), unique=True, index=True)
role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))
def __repr__(self):
return '' % self.username
# 视图函数
@app.route('/', methods=['GET', 'POST'])
def index():
form = NameForm()
if form.validate_on_submit():
user = User.query.filter_by(username=form.name.data).first()
if user is None:
user = User(username=form.name.data)
db.session.add(user)
session['known']=False
else:
session['known']=True
session['name'] = form.name.data
form.name.data=''
return redirect(url_for('index'))
return render_template('index.html',
form=form, name=session.get('name'),
known=session.get('known', False))
@app.route('/user/')
def user(name):
return render_template('user.html', name = name)
@app.errorhandler(404)
def page_not_found(e):
return render_template('404.html'), 404
@app.errorhandler(500)
def internal_server_error(e):
return render_template('500.html'), 500
if __name__ == '__main__':
# app.run(debug=True)
manager.run()
win下，不配置环境变量，初始化数据库迁移
【已解决】如何运行Flask-Migrate的db init
from app import db, app
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
migrate = Migrate(app, db)
manager = Manager(app)
manager.add_command("db", MigrateCommand)
if __name__ == "__main__":
manager.run()
jinja2自定义过滤器
当前app的所有过滤器app.jinja_env.filters
通过改变jinja2环境变量（不建议）
# flask1.0.2， py3.6
from jinja2 import environment
def test(obj):
return str(obj)
environment.DEFAULT_FILTERS["test"] = test
print(environment.DEFAULT_FILTERS)
直接给当前app添加过滤器，不会添加到jinjia2默认过滤器中
app.jinja_env.filters["test"]=test
通过添加方法添加（普通）
app.add_template_filter(test,"test")
通过装饰器添加（简单）
@app.template_filter("test")
def test(obj):
return str(obj)
jinja2加载静态文件
 }})
创建表
app = Flask(import_name=__name__) # type:Flask
app.config["SQLALCHEMY_DATABASE_URI"] = "mysql+pymysql://root:[email protected]:3306/flask"
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app) # type:SQLAlchemy
class User(db.Model):
__tablename__ = "users"
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
username = db.Column(db.String(length=80), nullable=False, unique=True, index=True)
age = db.Column(db.Integer, nullable=False)
email = db.Column(db.String(length=120), nullable=False, unique=True)
db.create_all()
根据app.config['SQLALCHEMY_ECHO'] = True查看sql语句
CREATE TABLE users (
id INTEGER NOT NULL AUTO_INCREMENT,
username VARCHAR(80) NOT NULL,
age INTEGER NOT NULL,
email VARCHAR(120) NOT NULL,
PRIMARY KEY (id),
UNIQUE (email)
)
查看表创建sql语句，发现缺少了username的添加索引和唯一性约束，所以建表sql语句仅供参考。。
mysql> show create table users;
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| users | CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(80) NOT NULL,
`age` int(11) NOT NULL,
`email` varchar(120) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `email` (`email`),
UNIQUE KEY `ix_users_username` (`username`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
主键自增
orm创建字段不需要添加autoincrement=True即id = db.Column(db.Integer, primary_key=True, autoincrement=True)
但是在原生sql语句是需要的id INTEGER NOT NULL AUTO_INCREMENT,PRIMARY KEY (id),
执行执行sql语句
参考了Python中该怎么防止SQL注入
from sqlalchemy import text
users = db.session.execute(text("select * from users where username =:username"), {'username': "root"})
users = db.session.execute(
text("select * from users where email like :con"),
{"con": "%gmail%"})
users = db.session.execute(
text("select * from users where username in :users"),
{"users": ["root", "test", "roo"]}
)
flask居然自己会缓存，清了浏览器缓存也没用：
app.config["TEMPLATES_AUTO_RELOAD"] = True app.config["SEND_FILE_MAX_AGE_DEFAULT"] = 0
uwsgi_config.ini 配置文件
[uwsgi]
http = 0.0.0.0:80
processes = 4
threads = 2
master = true
pythonpath = /root/WechatTest
wsgi-file = /root/WechatTest/app.py
callable = app
memory-report = true