Flask是一个使用 Python 编写的轻量级 Web 应用框架。其 WSGI 工具箱采用 Werkzeug ，模板引擎则使用 Jinja2。
Flask是一个轻量级的可定制框架，使用Python语言编写，较其他同类型框架更为灵活、轻便、安全且容易上手。
它可以很好地结合MVC模式进行开发，开发人员分工合作，小型团队在短时间内就可以完成功能丰富的中小型网站或Web服务的实现。
另外，Flask还有很强的定制性，用户可以根据自己的需求来添加相应的功能，在保持核心功能简单的同时实现功能的丰富与扩展，其强大的插件库可以让用户实现个性化的网站定制，开发出功能强大的网站。
在本微小项目应用的flask程序里实现了系统的登陆、注销、主页面、用户信息的查询、增加、删除、修改等功能。
关于主框架
代码语言：javascript复制# 将原生SQL语句返回结果集转换为字典 def datatodict():
# 检查登陆情况 def login_check(): login.html
# 上下文钩子 def my_context_process():
# 错误处理-404页面 @app.errorhandler(404) def internal_error(error): 404.html
# 错误处理-500页面 @app.errorhandler(500) def internal_error(error): 500.html
# 登陆页面 @app.route("/") def login(): login.html
# 登录页面的提交验证 @app.route("/login") def slogin(): home.html
# 注销页面 @app.route("/logout") def logout(): login.html
# 管理系统主页面 @app.route('/home') def home(): home.html
# 当前信息主页面 @app.route('/userinfo') def userinfo(): userinfo.html
# 添加用户主页面 @app.route('/userinfo/useradd') def useradd(): useradd.html
# 添加用户主页面响应 @app.route('/userinfo/useradd') def useradd(): userinfo.html
# 删除用户主页面提交响应 @app.route('/userinfo/userdelete') def userdelete(): userinfo.html
# 修改用户主页面 @app.route('/userinfo/userupdate/<userid>') def userupdate(): userupdate.html
# 修改用户主页面响应 @app.route('/userinfo/userupdate/<userid>') def userupdate(): userinfo.html
import config
from exts import db
from functools import wraps
from flask import Flask,render_template,request,url_for,session,redirect,flash
from flask_paginate import Pagination,get_page_parameter
from flask_sqlalchemy import SQLAlchemy
from models import UserInfo,XxxInfo
from datetime import datetime
app = Flask(__name__)
# 从config.py文件中获取数据库配置信息
app.config.from_object(config)
db = SQLAlchemy(app)
if __name__ == '__main__':
app.run()系统常用到的几个标准函数
代码语言：javascript复制# 将原生SQL语句返回结果转换为字典
def datatodict(resultProxy,fetch):
#resultProxy = db.session.execute(sql, params, bind=db.get_engine(bind=bind))
if fetch == 'one':
result_tuple = resultProxy.fetchone()
if result_tuple:
result = dict(zip(resultProxy.keys(), list(result_tuple)))
else:
return None
else:
result_tuple_list = resultProxy.fetchall()
if result_tuple_list:
result = []
keys = resultProxy.keys()
for row in result_tuple_list:
result_row = dict(zip(keys, row))
result.append(result_row)
else:
return None
return result
# 检查登陆情况
def login_check(func):
@wraps(func)
def wrapper(*args,**kwargs):
if session.get('userid'):
return func(*args, **kwargs)
else:
return redirect(url_for('login'))
return wrapper
# 上下文钩子
@app.context_processor
def my_context_processor():
userid = session.get('userid')
if userid:
userinfo = UserInfo.query.filter(UserInfo.userid == userid).first()
if userinfo:
return {'userinfo': userinfo}
return {}定制错误处理响应页面
代码语言：javascript复制# -------------------------错误管理------------------------
# 错误处理-404页面
@app.errorhandler(404)
def internal_error(error):
return render_template('404.html'),404
# 错误处理-500页面
@app.errorhandler(500)
def internal_error(error):
db.session.rollback()
return render_template('500.html'),500登陆管理，包括登陆、注销页面和提交验证
代码语言：javascript复制# -------------------------登陆管理------------------------
# 登陆页面
@app.route('/',methods=['GET','POST'])
def login():
return render_template('login.html')
# 登录页面的提交验证
@app.route('/login',methods=['POST'])
def slogin():
username = request.form['username']
password = request.form['password']
userinfo = UserInfo.query.filter(UserInfo.username == username,UserInfo.password == password).first()
if userinfo:
session['userid'] = userinfo.userid
return redirect(url_for('home'))
else:
return render_template('login.html',errorinfo='密码或账户输入错误')
# 注销登录
@app.route('/logout')
def logout():
session.clear()
return redirect(url_for('login'))系统主页面
代码语言：javascript复制# -------------------------主界面管理------------------------
# 管理系统主页面
@app.route('/home')
@login_check
def home():
return render_template('home.html')用户主页面，里面可进行数据的查询、新增、修改、删除
代码语言：javascript复制# -------------------------用户界面管理------------------------
# 用户信息主页面
@app.route('/userinfo/',methods=['GET', 'POST'])
def userinfo():
# 获取当前页
page = request.args.get('page', 1,type=int)
# 初始化参数值
usernamestr='%'
personalnamestr='%'
# POST提交获取各提交参数，写入session，并将页码置为1
if request.method == 'POST':
session['username'] = request.form['username']
session['personalname'] = request.form['personalname']
page=1
# 获取session值，如果存在或有值，则写入参数
if session.get('username') :
usernamestr = "%" session['username'] "%"
if session.get('personalname') :
personalnamestr = "%" session['personalname'] "%"
# sql主题语句
sqlpart="select userid,username,password,personalname,birthday,sex,phone,postcard,address from userinfo "
# where主体语句
wherepart = " where 1=1 and username like '{usernamestr}' and personalname like '{personalnamestr}'"
# order by 主体语句
orderbypart=" ORDER BY userid ASC "
# 分页语句
limitpart=" LIMIT {limit} offset {offset} "
# 每页记录行数暂时内定5
limit=5
# 获取当前偏移量
offset=(5 * int(page)-5)
# 把sql主体语句和where主体语句的SQL合并起来，获取总页数
sqlcount = "select count(*) from ( " sqlpart wherepart " )"
# sql语句，参数赋值
sqlcount=sqlcount.format(usernamestr=usernamestr,personalnamestr=personalnamestr)
total = db.session.execute(sqlcount).fetchone()[0]
sql = sqlpart wherepart orderbypart limitpart
# sql语句，参数赋值
sql = sql.format(limit=limit, offset=offset,usernamestr=usernamestr,personalnamestr=personalnamestr)
# 获取执行结果
data = db.session.execute(sql).all()
# 获取分页代码
pagination = Pagination(page=page, total=total, per_page=5)
# 将数据和分页代码传给页面
return render_template('userinfo.html', pagedata=data, pagination=pagination)用户增加界面和提交验证
代码语言：javascript复制# 添加用户提交
@app.route('/userinfo/useradd',methods=['GET', 'POST'])
def useradd():
# Bootstrap提供的alert样式，依次为：‘success’、‘info’、‘warning’、‘danger’。
if request.method == 'GET':
return render_template('useradd.html')
elif request.method == 'POST':
username = request.form.get('username',type=str,default=None)
password = request.form.get('password',type=str,default=None)
personalname = request.form.get('personalname',type=str,default=None)
birthday = request.form.get('birthday',type=str,default=None)
sex = request.form.get('sex',type=str,default='男')
phone = request.form.get('phone',type=str,default=None)
postcard = request.form.get('postcard',type=str,default=None)
address = request.form.get('address',type=str,default=None)
birthday=datetime.strptime(birthday, '%Y-%m-%d').date()
createdate = datetime.now()
modifydate = datetime.now()
createuserid=session.get('userid')
sql = "select count(*) from userinfo where username='{}'".format(username)
isexist = db.session.execute(sql).fetchone()[0]
if isexist:
flash('该用户已经存在！','danger')
return redirect('/userinfo/useradd')
else:
sql = "insert into userinfo (username,password,personalname,birthday,sex,phone,postcard,address,createdate,modifydate,createuserid) "
"values(:username,:password,:personalname,:birthday,:sex,:phone,:postcard,:address,:createdate,:modifydate,:createuserid)"
params={"username":username,
"password":password,
"personalname":personalname,
"birthday":birthday,
"sex":sex,
"phone":phone,
"postcard":postcard,
"address":address,
"createdate":createdate,
"modifydate":modifydate,
"createuserid":createuserid}
db.session.execute(sql,params)
db.session.commit()
return redirect('/userinfo/')用户删除和返回
代码语言：javascript复制# 删除用户提交响应
from flask import jsonify
@app.route('/userinfo/userdelete')
def userdelete():
userid = request.values.get("userid")
sql = "delete from userinfo where userid=:userid"
params = {"userid": userid}
from sqlalchemy.exc import SQLAlchemyError
try:
db.session.execute(sql, params)
db.session.commit()
return jsonify({"code": 200, "message": "删除成功"})
except SQLAlchemyError as e:
db.session.rollback()
return jsonify({"code": 400, "message": "删除错误"})
finally:
db.session.close()用户变更页面和提交验证
代码语言：javascript复制# 变更用户信息
@app.route('/userinfo/userupdate/<int:userid>', methods=['GET', 'POST'])
def userupdate(userid):
if request.method == 'GET':
sql = "select userid,username,password,personalname,birthday,sex,phone,postcard,address from userinfo where userid=:userid"
params = {"userid": userid}
user = db.session.execute(sql, params)
userdict=datatodict(user,'one')
return render_template('userupdate.html',user = userdict)
else:
username = request.form.get('username', type=str, default=None)
password = request.form.get('password', type=str, default=None)
personalname = request.form.get('personalname', type=str, default=None)
birthday = request.form.get('birthday', type=str, default=None)
sex = request.form.get('sex', type=str, default='男')
phone = request.form.get('phone', type=str, default=None)
postcard = request.form.get('postcard', type=str, default=None)
address = request.form.get('address', type=str, default=None)
birthday = datetime.strptime(birthday, '%Y-%m-%d').date()
modifydate = datetime.now()
sql = "update userinfo "
"set "
" username=:username,"
" password=:password,"
" personalname=:personalname,"
" birthday=:birthday,"
" sex=:sex,"
" phone=:phone,"
" postcard=:postcard,"
" address=:address,"
" modifydate=:modifydate"
" where userid=:userid"
params = {"username": username,
"password": password,
"personalname": personalname,
"birthday": birthday,
"sex": sex,
"phone": phone,
"postcard": postcard,
"address": address,
"modifydate": modifydate,
"userid": userid}
print(params)
db.session.execute(sql, params)
db.session.commit()
return redirect('/userinfo')
