Flask学习黑马程序员-6节课入门Flask框架web开发视频（中途撤退，寻找py3教程）

文章目录

postman工具
get和post
如何给路由传参解析
@app.route('')这个叫视图函数
Jinja2模板引擎
动态传参
注释、变量代码块以及控制代码块的使用
注释：ctrl+/
变量代码块使用
控制代码块的使用 if for等（for循环）
过滤器的使用（比如小写转大写，获取第几个字符之类的）
web表单及验证
flash消息闪现，给模板传递消息，消息加密（做混淆用）
表单样式的显示（使用flask_wtf模板创建表单）
模板表单的验证 csrf_token
Flask中使用SQL数据库 SQLAlchemy（flask_sqlalchemy）（如果是使用mysql数据库，安装flask_mysqldb）
mysql数据模型的定义常用SQLAlchemy字段类型/列选项/关系选项
数据库基本操作，增删改 db.session

Python-flask视频网站搭建

用flask-做一个资源网站(part1)-项目

黑马程序员-6节课入门Flask框架web开发视频

查看虚拟环境

Microsoft Windows [版本 10.0.18363.1256]
(c) 2019 Microsoft Corporation。保留所有权利。C:\Users\Dontla>virtualenv --version
virtualenv 20.3.1 from d:\20191031_tensorflow_yolov3\python\lib\site-packages\virtualenv\__init__.pyC:\Users\Dontla>

postman工具

https://www.postman.com/

get和post

如何给路由传参解析

@app.route(’’)这个叫视图函数

Jinja2模板引擎

动态传参

flask_template_demo.py

# -*- coding: utf-8 -*-
"""
@File    : flask_template_demo.py
@Time    : 2021/1/26 16:41
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_templateapp = Flask(__name__)@app.route('/')
def hello_world():url_str = 'www.baidu.com'return render_template('index.html', url_str=url_str)if __name__ == '__main__':app.run()

index.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>FLASK TEST</title>
</head>
<body>这是模板<br>这是首页<br>{{url_str}} <br>
</body>
</html>

注释、变量代码块以及控制代码块的使用

注释：ctrl+/

<!---->

变量代码块使用

# -*- coding: utf-8 -*-
"""
@File    : flask_template_demo.py
@Time    : 2021/1/26 16:41
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_templateapp = Flask(__name__)@app.route('/')
def hello_world():url_str = 'www.baidu.com'my_list = [1, 2, 3, 4, 5]my_dict = {'name': '黑马', 'url': 'www.tencent.com'}return render_template('index.html', url_str=url_str, my_list=my_list, my_dict=my_dict)if __name__ == '__main__':app.run()

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>FLASK TEST</title>
</head>
<body>
这是模板<br>
这是首页<br>
{{url_str}} <br>
{{my_list}} <br>
{{my_list.2}} <br>
{{my_list[2]}} <br>
{{my_dict}} <br>
{{my_dict.name}} <br>
{{my_dict['name']}} <br>
</body>
</html>

控制代码块的使用 if for等（for循环）

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>FLASK TEST</title>
</head>
<body>
这是模板<br>
这是首页<br>
{{url_str}} <br>
{{my_list}} <br>
{{my_list.2}} <br>
{{my_list[2]}} <br>
{{my_dict}} <br>
{{my_dict.name}} <br>
{{my_dict['name']}} <br><hr>{% for i in my_list %}{% if i >=3 %}{{i}} <br>{% endif %}
{% endfor %}
</body>
</html>

# -*- coding: utf-8 -*-
"""
@File    : flask_template_demo.py
@Time    : 2021/1/26 16:41
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_templateapp = Flask(__name__)@app.route('/')
def hello_world():url_str = 'www.baidu.com'my_list = [1, 2, 3, 4, 5]my_dict = {'name': '黑马', 'url': 'www.tencent.com'}return render_template('index.html', url_str=url_str, my_list=my_list, my_dict=my_dict)if __name__ == '__main__':app.run()

过滤器的使用（比如小写转大写，获取第几个字符之类的）

web表单及验证

# -*- coding: utf-8 -*-
"""
@File    : flask_WTF.py
@Time    : 2021/1/27 14:10
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_template, requestapp = Flask(__name__)@app.route('/', methods=["GET", "POST"])
def index():if request.method == 'POST':username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')if not all([username, password, password2]):return '参数不完整'else:return 'success'return render_template('index_WTF.html')if __name__ == '__main__':app.run(debug=True)

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>flask_WTF</title>
</head>
<body>
<form method="post"><label>用户名:</label><input type="text" name="username"><br><label>密码:</label><input type="password" name="password"><br><label>确认密码:</label><input type="password" name="password2"><br><input type="submit" value="提交"><br>
</form>
</body>
</html>

flash消息闪现，给模板传递消息，消息加密（做混淆用）

flask_WTF.py

# -*- coding: utf-8 -*-
"""
@File    : flask_WTF.py
@Time    : 2021/1/27 14:10
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_template, request, flashapp = Flask(__name__)
app.secret_key = '12345678'  # 随便填@app.route('/', methods=["GET", "POST"])
def index():if request.method == 'POST':username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')if not all([username, password, password2]):# return '参数不完整'flash('参数不完整')else:# return 'success'return 'sucess'return render_template('index_WTF.html')if __name__ == '__main__':app.run(debug=True)

index_WTF.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>flask_WTF</title>
</head>
<body>
<form method="post"><label>用户名:</label><input type="text" name="username"><br><label>密码:</label><input type="password" name="password"><br><label>确认密码:</label><input type="password" name="password2"><br><input type="submit" value="提交"><br>{% for message in get_flashed_messages() %}{{ message }}{% endfor %}
</form>
</body>
</html>

表单样式的显示（使用flask_wtf模板创建表单）

https://www.bilibili.com/video/BV17W41177oE?p=16

# -*- coding: utf-8 -*-
"""
@File    : flask_WTF.py
@Time    : 2021/1/27 14:10
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_template, request, flash
from flask_wtf import FlaskForm
from wtforms import SubmitField, PasswordField, StringFieldapp = Flask(__name__)
app.secret_key = '12345678'  # 随便填# 自定义表单类
class LoginForm(FlaskForm):username = StringField('用户名:')password = PasswordField('密码:')password2 = PasswordField('确认密码:')submit = SubmitField('提交')@app.route('/form', methods=['GET', 'POST'])
def login():login_form = LoginForm()# 1. 判断请求方式if request.method == 'POST':# 2. 获取请求的参数username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')# 3. 验证参数. WTF可以一句话就实现所有的校验# 我们没有CSRF tokenif login_form.validate_on_submit():print(username, password)return 'success'else:flash('参数有误')return render_template('index_WTF.html', form=login_form)@app.route('/', methods=["GET", "POST"])
def index():if request.method == 'POST':username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')if not all([username, password, password2]):# return '参数不完整'flash('参数不完整')else:# return 'success'return 'sucess'return render_template('index_WTF.html')if __name__ == '__main__':app.run(debug=True)

index_WTF.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>flask_WTF</title>
</head>
<body>
<form method="post"><label>用户名:</label><input type="text" name="username"><br><label>密码:</label><input type="password" name="password"><br><label>确认密码:</label><input type="password" name="password2"><br><input type="submit" value="提交"><br>{% for message in get_flashed_messages() %}{{ message }}{% endfor %}
</form><hr><form method="post">{{ form.csrf_token() }}{{ form.username.label }}{{ form.username }} <br>{{ form.password.label }}{{ form.password }} <br>{{ form.password2.label }}{{ form.password2 }} <br>{{ form.submit}} <br>
</form>
</body>
</html>

模板表单的验证 csrf_token

常用验证函数

怎么使用？

老师说validators是复数，所以可以传个列表，这推导？？

但这写个tuple是啥意思？反正就是可迭代对象就行？（不能用tuple，会报错，只能用列表）

# -*- coding: utf-8 -*-
"""
@File    : flask_WTF.py
@Time    : 2021/1/27 14:10
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask, render_template, request, flash
from flask_wtf import FlaskForm
from wtforms import SubmitField, PasswordField, StringField
from wtforms.validators import DataRequired, EqualToapp = Flask(__name__)
app.secret_key = '12345678'  # 随便填# 自定义表单类
class LoginForm(FlaskForm):username = StringField('用户名:', validators=[DataRequired()])password = PasswordField('密码:', validators=[DataRequired()])password2 = PasswordField('确认密码:', validators=[DataRequired(), EqualTo('password', '提示：密码填入不一致')])submit = SubmitField('提交')@app.route('/form', methods=['GET', 'POST'])
def login():login_form = LoginForm()# 1. 判断请求方式if request.method == 'POST':# 2. 获取请求的参数username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')# 3. 验证参数. WTF可以一句话就实现所有的校验# 我们没有CSRF tokenif login_form.validate_on_submit():print(username, password)return 'success'else:flash('参数有误')return render_template('index_WTF.html', form=login_form)@app.route('/', methods=["GET", "POST"])
def index():if request.method == 'POST':username = request.form.get('username')password = request.form.get('password')password2 = request.form.get('password2')if not all([username, password, password2]):# return '参数不完整'flash('参数不完整')else:# return 'success'return 'success'return render_template('index_WTF.html')if __name__ == '__main__':app.run(debug=True)

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>flask_WTF</title>
</head>
<body>
<form method="post"><label>用户名:</label><input type="text" name="username"><br><label>密码:</label><input type="password" name="password"><br><label>确认密码:</label><input type="password" name="password2"><br><input type="submit" value="提交"><br>{% for message in get_flashed_messages() %}{{ message }}{% endfor %}
</form><hr><form method="post">{{ form.csrf_token() }}{{ form.username.label }}{{ form.username }} <br>{{ form.password.label }}{{ form.password }} <br>{{ form.password2.label }}{{ form.password2 }} <br>{{ form.submit}} <br>
</form>
</body>
</html>

Flask中使用SQL数据库 SQLAlchemy（flask_sqlalchemy）（如果是使用mysql数据库，安装flask_mysqldb）

# -*- coding: utf-8 -*-
"""
@File    : flask_sqlalchemy_demo.py
@Time    : 2021/2/5 14:49
@Author  : Dontla
@Email   : sxana@qq.com
@Software: PyCharm
"""
from flask import Flask
from flask_sqlalchemy import SQLAlchemyapp = Flask(__name__)
# 配置数据库地址
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:mysql@127.0.0.1/flask_sql_demo'
# 跟踪数据库修改 -- 不建议开启（消耗性能，同时未来版本中会移除）
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)@app.route('/')
def hello_world():return 'Hello World'if __name__ == '__main__':app.run(debug=False)

在电脑上还要创建sql数据库？？

装好了，按照这个安装就行

数据库mysql是什么？win10如何安装使用mysql?

然后控制台执行命令，登入数据库：

C:\Users\Dontla>mysql -u root -p
Enter password: ****
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 8.0.23 MySQL Community Server - GPLCopyright (c) 2000, 2021, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>

创建数据库：

mysql> create database flask_demo charset=utf8;
Query OK, 1 row affected, 1 warning (0.02 sec)mysql>

使用数据库：

mysql> use flask_sql_demo;
Database changed
mysql>

显示数据库表单：

mysql> show tables;
Empty set (0.01 sec)mysql>

mysql数据模型的定义常用SQLAlchemy字段类型/列选项/关系选项

表格式：

两个表做两个class

代码看下一节

数据库基本操作，增删改 db.session

我勒个去，应该找个python3的教程的，这个python2很多库用法不支持，替换也替换不了。。。。https://www.bilibili.com/video/BV17W41177oE?p=20&spm_id_from=pageDriver到此为止，再见！