gilbert-yuan/quart_learn

flask

内置方法及学习使用注释

Flask

render_template 构造模版，传html模版和必须的数据，返回对应的完整的html 字符串/文件

redirect 重定向传入值是 url 自付串

url_for 构造一个完整的url 传入方法名

from flask import render_template, redirect, url_for, Flask

app = Flask(__name__)
@app.route('/home/<id>')
def home():
    return render_template('index.html')  
 
redirect(url_for('home', id=12))

request

session 全局变量 一般用来存储登录的session状态

g 全局变量 一般用来存储数据库db

flash 传入实时提醒信息，在前端通过 get_flashed_messages 获取信息

Flashes a message to the next request. In order to remove the

flashed message from the session and to display it to the user,

the template has to call :func:get_flashed_messages

functools

wraps 用来写装饰器的

from functools import wraps

def login_required(f):
    @wraps(f)
    def wrap(*args, **kwargs):
        if 'logged_in' in '':
            return f(*args, **kwargs)
        else:
            return ''
    return wrap

SQLLite3 连接db 实现小功能

import sqlite3
# create a new database if the database doesn't already exist
with sqlite3.connect('sample.db') as connection:
    # get a cursor object used to execute SQL commands
    c = connection.cursor()
    # create the table
    c.execute('CREATE TABLE posts(title TEXT, details TEXT)')
    # insert dummy data into the table
    c.execute('INSERT INTO posts VALUES("Good", "I\'m good.")')
    c.execute('INSERT INTO posts VALUES("Well", "I\'m well.")')
    c.execute('INSERT INTO posts VALUES("Excellent", "I\'m excellent.")')
    c.execute('INSERT INTO posts VALUES("Okay", "I\'m okay.")')

简单连接数据库并进行取数据展示的代码

from flask import Flask, render_template, redirect, \
    url_for, request, session, flash, g
import sqlite3
app = Flask(__name__)
app.database = 'sample.db' # 根目录下随意的一个db文件
# connect to database
def connect_db():
    return sqlite3.connect(app.database)
    
g.db = connect_db()
cur = g.db.execute('select * from posts')
posts = [dict(title=row[0], description=row[1]) for row in cur.fetchall()]
g.db.close()

使用 SQLAlchemy 库

from flask import Flask, render_template, redirect, \
    url_for, request, session, flash
from functools import wraps
from flask.ext.sqlalchemy import SQLAlchemy
app = Flask(__name__)
db = SQLAlchemy(app)

# from models import *


# models.py

#from app import db
class BlogPost(db.Model):
    __tablename__ = 'posts'
    
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String, nullable=False)
    description = db.Column(db.String, nullable=False)
    
    def __init__(self, title, description):
        self.title = title
        self.description = description    
    
    def __repr__(self):
        return "<title {}>".format(self.title)

from app import db
from models import BlogPost

# create the database and the db table
db.create_all()

# insert data
db.session.add(BlogPost("Good", "I\'m good."))
db.session.add(BlogPost("Well", "I\'m well."))
db.session.add(BlogPost("Excellent", "I\'m excellent."))
db.session.add(BlogPost("Okay", "I\'m okay."))

# commit the changes
db.session.commit()

Bcrypt 对整个App进行处理，获得加密器

from flask.ext.bcrypt import Bcrypt
from flask.ext.login import LoginManager
app = Flask(__name__)
bcrypt = Bcrypt(app)
# 可进行加密 hunter2 字符
pw_hash = bcrypt.generate_password_hash('hunter2')