Flask不同于Django，Django在创建程序时自动得到必要的目录文件，而Flask则只有一个空文件夹，所以关于Flask项目的目录我们需要自行配置。
首先利用pycharm创建一个项目，在根目录下创建一个app文件夹（app文件）、一个utils文件夹（用于放数据库连接池）、一个manage.py文件和一个settings.py文件。这里我还创建了一个auth文件夹，写了一个验证登录的py文件
首先，我们要在app文件夹下依次创建一下内容：
- static文件夹：用于放静态文件
- templates文件夹：用于放置html模板文件
- views文件夹：用于放置视图函数
- __init__.py文件：注册app到启动文件，一会儿我们会在这里大做文章
- models.py文件：用于放置创建表的类
在__init__.py中，需要做的是引入Flask-SQLAlchemy、创建app、设置配置文件、注册蓝图和注册组件
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Flask
from auth.auth import Auth
from flask_session import Session
# 1. 引入Flask-SQLAlchemy
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()#实例化SQLAlchemy
from .views.account import account
from .views.main import main
from .views.user import user
# 3. 导入models中的表
from .models import *
#创建app
def create_app():
app = Flask(__name__)
app.debug = True
app.secret_key = 'sdiusdfsdf'#自定义的session秘钥
# 设置配置文件
app.config.from_object('settings.DevelopmentConfig')
# 注册蓝图
app.register_blueprint(account)
app.register_blueprint(user)
app.register_blueprint(main)
# 注册组件
# Session(app)
Auth(app)
# 2. 注册 Flask-SQLAlchemy
# 这个对象在其他地方想要使用
# SQLAlchemy(app)
db.init_app(app)
return app
#得到了一个app
app文件夹下的_init__.py
然后，在启动文件manage.py中导入创建的app，创建自定义命令后写下run
#!/usr/bin/env python
# -*- coding:utf-8 -*-
"""
被毙掉了
# 5. 创建和删除表
以后执行db.create_all()
以后执行db.drop_all()
新第5步：
安装 pip3 install Flask-Migrate
"""
import os
from flask_script import Manager, Server
# 5.1 导入
from flask_migrate import Migrate, MigrateCommand
from app import create_app, db
app = create_app()
manager = Manager(app)
# 5.2 创建migrate示例
migrate = Migrate(app, db)
@manager.command
def custom(arg):
"""
自定义命令
python manage.py custom 123
:param arg:
:return:
"""
print(arg)
@manager.option('-n', '--name', dest='name')
@manager.option('-u', '--url', dest='url')
def cmd(name, url):
"""
自定义命令
执行： python manage.py cmd -n wupeiqi -u http://www.oldboyedu.com
:param name:
:param url:
:return:
"""
print(name, url)
@manager.command
def import_news(path):
"""
批量导入
:param name:
:param url:
:return:
"""
import xlrd
from xlrd.book import Book
from xlrd.sheet import Sheet
from xlrd.sheet import Cell
workbook = xlrd.open_workbook(path)
sheet_names = workbook.sheet_names()
# sheet = workbook.sheet_by_name('工作表1')
sheet = workbook.sheet_by_index(0)
# 循环Excel文件的所有行
for row in sheet.get_rows():
# print(row)
# 循环一行的所有列
for col in row:
# 获取一个单元格中的值
print(col.value, end=';')
print('')
"""
# 数据库迁移命名
python manage.py db init
python manage.py db migrate
python manage.py db upgrade
"""
# 5.3 创建db命令，以后在数据库操作的时候都可使用db
manager.add_command('db', MigrateCommand)
"""
# 自定义命令
python manage.py runserver
"""
manager.add_command("runserver", Server())
"""
生成当前环境的所有依赖： requirements.txt
pip3 freeze > requirements.txt
生成当前程序的所有依赖： requirements.txt
pip3 install pipreqs
pipreqs ./
"""
if __name__ == "__main__":
manager.run()
manage.py
接下来在settings.py文件中配置好相应的数据库信息，在utils文件夹下创建文件，写入数据库连接池的内容
#!/usr/bin/env python
# -*- coding:utf-8 -*-
import redis
class BaseConfig(object):
SESSION_TYPE = 'redis' # session类型为redis
SESSION_KEY_PREFIX = 'session:' # 保存到session中的值的前缀
SESSION_PERMANENT = False # 如果设置为True，则关闭浏览器session就失效。
SESSION_USE_SIGNER = False # 是否对发送到浏览器上 session:cookie值进行加密
SQLALCHEMY_DATABASE_URI = "mysql+pymysql://root:123@127.0.0.1:3306/flask_cata?charset=utf8"
#数据库用户名:密码@host:port/数据库名?编码
SQLALCHEMY_POOL_SIZE = 2
SQLALCHEMY_POOL_TIMEOUT = 30
SQLALCHEMY_POOL_RECYCLE = -1
# 追踪对象的修改并且发送信号
SQLALCHEMY_TRACK_MODIFICATIONS = False
class ProductionConfig(BaseConfig):
pass
class DevelopmentConfig(BaseConfig):
pass
class TestingConfig(BaseConfig):
pass
settings.py
import time
import pymysql
import threading
from DBUtils.PooledDB import PooledDB, SharedDBConnection
POOL = PooledDB(
creator=pymysql, # 使用链接数据库的模块
maxconnections=6, # 连接池允许的最大连接数，0和None表示不限制连接数
mincached=2, # 初始化时，链接池中至少创建的空闲的链接，0表示不创建
maxcached=5, # 链接池中最多闲置的链接，0和None不限制
maxshared=3, # 链接池中最多共享的链接数量，0和None表示全部共享。PS: 无用，因为pymysql和MySQLdb等模块的 threadsafety都为1，所有值无论设置为多少，_maxcached永远为0，所以永远是所有链接都共享。
blocking=True, # 连接池中如果没有可用连接后，是否阻塞等待。True，等待；False，不等待然后报错
maxusage=None, # 一个链接最多被重复使用的次数，None表示无限制
setsession=[], # 开始会话前执行的命令列表。如：["set datestyle to ...", "set time zone ..."]
ping=0,
# ping MySQL服务端，检查是否服务可用。# 如：0 = None = never, 1 = default = whenever it is requested, 2 = when a cursor is created, 4 = when a query is executed, 7 = always
# host='47.93.4.198',
host='127.0.0.1',#本机host
port=3306,#数据库默认端口即3306
user='root',#数据库用户名
password='123',#数据库密码
database='flask_cata',#数据库名
charset='utf8'
)
utils\pool\db_pool.py
"""
# 方式一
# helper = SQLHelper()
# helper.open()
# result = helper.fetchone('select * from users where name=%s and pwd = %s',[request.form.get('user'),request.form.get('pwd'),])
# helper.close()
# 方式二：
# with SQLHelper() as helper:
# result = helper.fetchone('select * from users where name=%s and pwd = %s',[request.form.get('user'),request.form.get('pwd'),])
# if result:
# current_app.auth_manager.login(result['name'])
# return redirect('/index')
"""
from utils.pool import db_pool
import pymysql
class SQLHelper(object):
def __init__(self):
self.conn = None
self.cursor = None
def open(self, cursor=pymysql.cursors.DictCursor):
self.conn = db_pool.POOL.connection()
self.cursor = self.conn.cursor(cursor=cursor)
def close(self):
self.cursor.close()
self.conn.close()
def fetchone(self, sql, params):
cursor = self.cursor
cursor.execute(sql, params)
result = cursor.fetchone()
return result
def fetchall(self, sql, params):
cursor = self.cursor
cursor.execute(sql, params)
result = cursor.fetchall()
return result
def __enter__(self):
self.open()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
# with SQLHelper() as obj:
#
# print(obj)
# print('正在执行')
utils\pool\sqlhelper.py
到这里，程序的基本框架就设定好了。
接下来就是具体项目的内容，这里举一个简单的栗子
在models.py中创建表
"""
# 方式一
# helper = SQLHelper()
# helper.open()
# result = helper.fetchone('select * from users where name=%s and pwd = %s',[request.form.get('user'),request.form.get('pwd'),])
# helper.close()
# 方式二：
# with SQLHelper() as helper:
# result = helper.fetchone('select * from users where name=%s and pwd = %s',[request.form.get('user'),request.form.get('pwd'),])
# if result:
# current_app.auth_manager.login(result['name'])
# return redirect('/index')
"""
from utils.pool import db_pool
import pymysql
class SQLHelper(object):
def __init__(self):
self.conn = None
self.cursor = None
def open(self, cursor=pymysql.cursors.DictCursor):
self.conn = db_pool.POOL.connection()
self.cursor = self.conn.cursor(cursor=cursor)
def close(self):
self.cursor.close()
self.conn.close()
def fetchone(self, sql, params):
cursor = self.cursor
cursor.execute(sql, params)
result = cursor.fetchone()
return result
def fetchall(self, sql, params):
cursor = self.cursor
cursor.execute(sql, params)
result = cursor.fetchall()
return result
def __enter__(self):
self.open()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
# with SQLHelper() as obj:
#
# print(obj)
# print('正在执行')
models.py
通过python manage.py db init python manage.py db migrate python manage.py db upgrade三条命令进行数据库迁移创建表，得到migrations文件夹
在views文件夹下创建视图函数，并配置路由。在templates文件夹下创建模板html，在static下创建静态文件，基本项目就成型了
views：
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Blueprint, request, render_template, redirect, session, current_app
from app import models
from app import db
from sqlalchemy import orm
account = Blueprint('account', __name__)
@account.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
"""
执行SQL
方式一：
result = db.session.query(models.User.id,models.User.name).all()
db.session.remove()
方式二：
result = models.Users.query.all()
"""
"""
示例：
# 通配符
ret = db.session.query(Users).filter(Users.name.like('e%')).all()
ret = db.session.query(Users).filter(~Users.name.like('e%')).all()
# 限制
ret = db.session.query(Users)[1:2]
# 排序
ret = db.session.query(Users).order_by(Users.name.desc()).all()
ret = db.session.query(Users).order_by(Users.name.desc(), Users.id.asc()).all()
db.session.remove()
"""
return render_template('login.html')
else:
return render_template('login.html')
account.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Blueprint, request, render_template, redirect
main = Blueprint('main', __name__)
@main.route('/index')
def index():
# with SQLHelper() as helper:
# user_list = helper.fetchall('select * from users',[])
return render_template('index.html')
main.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import Blueprint
user = Blueprint('user', __name__)
@user.route('/users')
def users():
return 'users'
user.py
templates:
{% extends 'layout.html' %}
{% block title %}首页{% endblock %}
{% block body %}
<table>
<h1>欢迎登录：{{ session.get('user') }}</h1>
<ul>
{% for row in user_list %}
<li>{{ row }}</li>
{% endfor %}
</ul>
</table>
{% endblock %}index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>{% block title %}{% endblock %}</title>
<!-- <link rel="stylesheet" href="/static/css/commons.css" /> -->
<link rel="stylesheet" href="{{ url_for('static',filename='css/commons.css') }}" />
{% block css %}{% endblock %}
</head>
<body>
<div class="pg-header"></div>
<div class="pg-body">
{% block body %}{% endblock %}
</div>
{% block js %}{% endblock %}
</body>
</html>
layout.html(基板)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form method="post">
<input type="text" name="user">
<input type="text" name="pwd">
<input type="submit" value="提交">
</form>
</body>
</html>
login.html
附：
alembic==0.9.6
blinker==1.4
certifi==2017.11.5
chardet==3.0.4
click==6.7
DBUtils==1.2
docopt==0.6.2
Flask==0.12.2
Flask-Migrate==2.1.1
Flask-Script==2.0.6
Flask-Session==0.3.1
Flask-SQLAlchemy==2.3.2
idna==2.6
itsdangerous==0.24
Jinja2==2.10
Mako==1.0.7
MarkupSafe==1.0
pipreqs==0.4.9
PyMySQL==0.8.0
python-dateutil==2.6.1
python-editor==1.0.3
PyTyrion==1.0.1
requests==2.18.4
six==1.11.0
SQLAlchemy==1.2.0
urllib3==1.22
Werkzeug==0.14.1
WTForms==2.1
xlrd==1.1.0
yarg==0.1.9
requirement.txt
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from flask import request, session,redirect
# 登录成功时 _request_ctx_stack.top.user = user
class Auth(object):
def __init__(self, app=None):
self.app = app
if app:
self.init_app(app)
def init_app(self, app):
app.auth_manager = self
app.before_request(self.check_login)
app.context_processor(self.auth_context_processor)
def auth_context_processor(self):
name = session.get('user')
return dict(current_user=name)
def check_login(self):
# print(request.url)
# print(request.path)
if request.path == '/login':
return None
if session.get('user'):
return None
return redirect('/login')
def permission(self):
pass
def login(self,data):
session['user'] = data
auth.py
