一、初始化配置
二、app实例的配置
三、before_request、after_request、errorhandler三个装饰器
四、blueprint蓝图
五、蓝图示例
六、CBV版视图函数
七、WTForms
八、SQLAlchemy in Flask
一、flask_demo1 初始化配置
from flask import Flask, render_template
app = Flask(__name__, template_folder='template', static_folder='static_file', static_url_path='/static')
@app.route('/')
def index():
return render_template('index.html')
if __name__ == '__main__':
app.run()
# template_folder 指定模板文件的寻找名称
# static_url_path='/static' ,（必须加上斜杠）一般不用改，当前端页面大量使用原文件路径，
# 但是新文件路径改变了之后，就可以写上这个，确保html页面中的路径不用改动
# 不设置，默认是static_folder的名字
# static_folder 这个是告诉服务器，静态文件的存放地址
# static_url_path 这个是前端通过浏览器访问服务器的静态文件时的地址，
# 设置了这个意思就是：
# 我服务器看到这个路径就知道你要访问我的静态文件，然后我再从我存放静态文件的文件夹中去取，我存放文件的文件夹就是static_folder
二、flask_demo2 app实例的配置
app.py
from flask import Flask,session
import flask_config
app = Flask(__name__)
app.config['DEBUG'] = True # 方式1
app.config.from_object(flask_config.Config) # 方式2
@app.route('/')
def index():
session['user'] = 'user' # 验证方式二可不可以配置上
return 'Hello World!'
if __name__ == '__main__':
app.run()
flask_config.py
class Config(object):
DEBUG = True
SECRET_KEY = '123456789'
REDIS = '127.0.0.1:6379'
MYSQL = '127.0.0.1:3306'
if __name__ == '__main__':
from flask import Flask
app = Flask(__name__)
for key in dir(Config):
if key.isupper():
print(key,type(key))
app.config[key] = getattr(Config,key)
# 和 app.config['DEBUG'] = True 一样的
三、flask_demo3 三个装饰器
from flask import Flask, render_template
app = Flask(__name__)
@app.before_request
def fumc1():
print('before1')
# return 'before1结束'
@app.before_request
def fumc2():
print('before2')
@app.before_request
def fumc3():
print('before3')
@app.after_request
def fumc4(res):
print('after1')
return res
@app.after_request
def fumc5(res):
print('after2')
return res
@app.after_request
def fumc6(res):
print('after3')
return res
@app.route('/')
def index():
print('index')
return 'Hello World!'
@app.errorhandler(404)
def error(e):
print('走了error')
print(e.name)
# Not Found
print(e.get_description())
# The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
return render_template('error.html')
if __name__ == '__main__':
app.run()
# 类似于django的中间件
# @app.after_request必须接收参数，且返回一个响应
# 执行顺序：
# before1
# before2
# before3
# index
# after3
# after2
# after1
# 如果函数在中途被返回（打开1的return），则执行顺序为：
# before1
# after3
# after2
# after1
# @app.errorhandler(404)函数中必须接收一个参数，否则报错。
所有函数都加装饰器
from flask import Flask,session,request,redirect,render_template
app = Flask(__name__)
app.secret_key = 'ASDFGHJKL'
# 写装饰器（一句话搞定）
@app.before_request
def check_login():
if session.get('user') or request.path == '/login/':
return None
next = request.path
return redirect('/login/?next=%s' % next)
@app.route('/index')
def index():
return '这是index页面'
@app.route('/home')
def home():
return '这是home页面'
@app.route('/login/',methods=('GET','POST'))
def login():
msg = ''
if request.method == 'POST':
username = request.form.get('username')
password = request.form.get('password')
if username == 'zhangsan' and password == '123':
session['user'] = username
next = request.args.get('next') or '/index'
return redirect(next)
else:
msg = '用户名或密码错误'
return render_template('login.html',msg=msg)
app.run()
# 这样做的不好之处是，如果访问本服务器没有的url也会让其登录，登录之后才告知没有该url。蓝图可解决只给蓝图内的函数加认证。
四、flask_demo4 blueprint蓝图
app.py
import flask_config
import flask_lantu1
import flask_lantu2
from flask import Flask
app = Flask(__name__)
app.config.from_object(flask_config.Config)
app.register_blueprint(flask_lantu1.addstu)
app.register_blueprint(flask_lantu2.delstu)
@app.route('/')
def index():
return 'Hello World!'
if __name__ == '__main__':
app.run()
# 插拔机制
# 定义蓝图、引入蓝图、注册蓝图
flask_lantu1.py
from flask import Blueprint,render_template
addstu = Blueprint("addstu", __name__,
template_folder="blueprint_temp",
static_folder="blueprint_static",
static_url_path="/static2")
@addstu.route("/add_stu")
def add():
return render_template("add_stu.html")
flask_lantu2.py
from flask import Blueprint
delstu = Blueprint("delstu", __name__)
@delstu.route("/del_stu")
def deletestu():
return "del_stu_blueprint"
blueprint_temp/add_stu.html
Title
1
2
3
图片：blueprint_static/f666.jpg
五、蓝图示例
before_request版登录验证蓝图.py
from flask import Blueprint,request,session,redirect
bp = Blueprint('bp',__name__)
@bp.before_request
def check_login():
if session.get('user') or request.path == '/login/':
return None
next = request.path
print('bp',next)
return redirect('/login/?next=%s' % next)
@bp.route('/bp1')
def bp1():
return 'This is 蓝图1'
@bp.route('/bp2')
def bp2():
return '这是蓝图2'
# 单独在蓝图中设置before_request，可以实现只访问蓝图中的url需要验证，如果输入的url不存在可立即提示不存在。
app.py
from flask import Flask,redirect,request,render_template,session
import before_request版登录验证蓝图
app = Flask(__name__)
app.secret_key='ASDF'
app.register_blueprint(before_request版登录验证蓝图.bp)
# session['user'] = 'username' # session放在有效的函数中才可使用，否则报错，因为不符合请求上下文。
@app.route('/')
def index():
return 'Hello World!'
@app.route('/home')
def home():
return 'Welcome to Home!'
@app.route('/login/',methods=('GET','POST'))
def login():
msg = ''
if request.method == 'POST':
username = request.form.get('username')
password = request.form.get('password')
if username == 'zhangsan' and password == '123':
session['user'] = username
next = request.args.get('next') or '/index'
print('flask',next)
return redirect(next)
else:
msg = '用户名或密码错误'
return render_template('login.html',msg=msg)
if __name__ == '__main__':
app.run()
templates/login.html
Title
{{ msg }}
六、flask_demo6 CBV版视图函数
app.py
from flask import Flask, views
import flask_demo2蓝图中的CBV
app = Flask(__name__)
app.register_blueprint(flask_demo2蓝图中的CBV.bp)
class Index(views.MethodView):
# methods = ['POST','GET']
def get(self):
# self.dispatch_request()
return 'GET'
def post(self):
return 'POST'
app.add_url_rule('/index', endpoint='class_index', view_func=Index.as_view(name='index'))
if __name__ == '__main__':
app.run()
flask_demo2蓝图中的CBV.py
from flask import Blueprint, views
bp = Blueprint("bluename", __name__)
class bpclass(views.MethodView):
def get(self):
return "blue_get"
bp.add_url_rule("/blue",endpoint="blue",view_func=bpclass.as_view(name="bpclass"))
CBV版.png
七、flask_demo7 之 WTForms
（pip install wtforms）
from flask import Flask, views, render_template, request, session
app = Flask(__name__)
from wtforms.fields import simple, core
from wtforms import Form
from wtforms import validators
class LoginForm(Form):
username = simple.StringField(
label="用户名",
validators=[
validators.DataRequired(message="数据不能为空"),
validators.Length(min=5, max=16, message="大于5小于16")
],
render_kw={"class": "1班"}
)
password = simple.PasswordField(
label="密码",
validators=[
validators.DataRequired(message="数据不能为空"),
validators.Length(min=5, max=16, message="大于5小于16"),
validators.Regexp(regex="\d+", message="密码必须为数字")
],
)
class Index(views.MethodView):
def get(self):
loginfm = LoginForm()
return render_template("index.html", fm=loginfm)
def post(self):
loginfm = LoginForm(request.form)
if not loginfm.validate():
return render_template("index.html", fm=loginfm)
session["user"] = "good！"
return "Hello"
app.add_url_rule("/index", endpoint="class_index", view_func=Index.as_view(name="123"))
class RegForm(Form):
hobby_init = []
# def __init__(self, hobby_list):
# self.hobby_list = hobby_list
# # self.hobby_init = []
# self.init_hobby()
# super(RegForm, self).__init__()
# def init_hobby(self):
# for index, item in enumerate(self.hobby_list):
# self.hobby_init.append([index, item])
username = simple.StringField(
label="用户名",
validators=[
# validators.DataRequired(message="数据不能为空"),
validators.Length(min=5, max=16, message="大于5小于16")
],
render_kw={"class": "username"}
)
password = simple.PasswordField(
label="密码",
validators=[
validators.DataRequired(message="数据不能为空"),
validators.Length(min=5, max=16, message="大于5小于16"),
validators.Regexp(regex="\d+", message="密码必须为数字")
],
)
repassword = simple.PasswordField(
label="密码",
validators=[
# validators.DataRequired(message="数据不能为空"),
validators.EqualTo("password", message="两次密码不一致")
],
)
gender = core.RadioField(
label="性别",
choices=(
(1, "女"),
(2, "男"),
(3, "保密")
),
coerce=int,
default=3
)
hobby = core.SelectMultipleField(
label="爱好",
choices=[[1, "cy"]],
coerce=int,
default=1
)
@app.route("/reg", methods=["GET", "POST"])
def reg():
if request.method == "GET":
# hobby_list = ["cy","hj","bd","ysd","啤酒泡枸杞","熬夜敷面膜"]
regfm = RegForm()
return render_template("reg.html", fm=regfm)
else:
regfm = RegForm(request.form)
if not regfm.validate():
return render_template("reg.html", fm=regfm)
print(regfm.data.get("hobby"), regfm.data.get("gender"))
return "注册成功"
if __name__ == '__main__':
app.run()
templates/index.html
Title
请登录：
templates/reg.html
Title