wtforms
WTForms是一个支持多个web框架的form组件,主要用于对用户请求数据进行验证。
两大作用:
- 生成HTML标签
- form表单验证
安装:
pip3 install wtforms
用户登录注册示例
1. 用户登录
当用户登录时候,需要对用户提交的用户名和密码进行多种格式校验。如:
用户不能为空;用户长度必须大于6;
密码不能为空;密码长度必须大于12;密码必须包含 字母、数字、特殊字符等(自定义正则);
2.用户注册
注册页面需要让用户输入:用户名、密码、密码重复、性别、爱好等。
代码实现:
from flask import Flask,request,render_template,session,current_app,g,redirect from wtforms import Form from wtforms.fields import simple from wtforms.fields import html5 from wtforms.fields import core from wtforms import widgets from wtforms import validators app = Flask(__name__) class LoginForm(Form): name = simple.StringField( validators=[ validators.DataRequired(message='用户名不能为空.'), # validators.Length(min=6, max=18, message='用户名长度必须大于%(min)d且小于%(max)d') ], widget=widgets.TextInput(), render_kw={'placeholder':'请输入用户名'} ) pwd = simple.PasswordField( validators=[ validators.DataRequired(message='密码不能为空.'), # validators.Length(min=8, message='用户名长度必须大于%(min)d'), # validators.Regexp(regex="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$@$!%*?&])[A-Za-z\d$@$!%*?&]{8,}", # message='密码至少8个字符,至少1个大写字母,1个小写字母,1个数字和1个特殊字符') ], render_kw={'placeholder':'请输入密码'} ) @app.route('/login',methods=['GET','POST']) def login(): if request.method == "GET": form = LoginForm() # print(form.name,type(form.name)) # form.name是StringField()对象, StringField().__str__ # print(form.pwd,type(form.pwd)) # form.pwd是PasswordField()对象,PasswordField().__str__ return render_template('login.html',form=form) form = LoginForm(formdata=request.form) if form.validate(): print(form.data) return redirect('https://www.luffycity.com/home') else: # print(form.errors) return render_template('login.html', form=form) class RegisterForm(Form): name = simple.StringField( label='用户名', validators=[ validators.DataRequired() ], widget=widgets.TextInput(), render_kw={'class': 'form-control'}, default='hui' ) pwd = simple.PasswordField( label='密码', validators=[ validators.DataRequired(message='密码不能为空.') ], widget=widgets.PasswordInput(), render_kw={'class': 'form-control'} ) pwd_confirm = simple.PasswordField( label='重复密码', validators=[ validators.DataRequired(message='重复密码不能为空.'), validators.EqualTo('pwd', message="两次密码输入不一致") ], widget=widgets.PasswordInput(), render_kw={'class': 'form-control'} ) email = html5.EmailField( label='邮箱', validators=[ validators.DataRequired(message='邮箱不能为空.'), # validators.Email(message='邮箱格式错误') ], widget=widgets.TextInput(input_type='email'), render_kw={'class': 'form-control'} ) gender = core.RadioField( label='性别', choices=( (1, '男'), (2, '女'), ), coerce=int # int("1") ) city = core.SelectField( label='城市', choices=( ('bj', '北京'), ('sh', '上海'), ) ) hobby = core.SelectMultipleField( label='爱好', choices=( (1, '篮球'), (2, '足球'), ), coerce=int ) favor = core.SelectMultipleField( label='喜好', choices=( (1, '篮球'), (2, '足球'), ), widget=widgets.ListWidget(prefix_label=False), option_widget=widgets.CheckboxInput(), coerce=int, default=[1, ] ) @app.route('/register', methods=['GET', 'POST']) def register(): if request.method == 'GET': form = RegisterForm() return render_template('register.html', form=form) form = RegisterForm(formdata=request.form) if form.validate(): print(form.data) return redirect('https://www.luffycity.com/home') return render_template('register.html', form=form) import helper class UserForm(Form): city = core.SelectField( label='城市', choices=(), coerce=int ) name = simple.StringField(label='姓名') def __init__(self,*args,**kwargs): super(UserForm,self).__init__(*args,**kwargs) self.city.choices=helper.fetch_all('select id,name from tb1',[],type=None) #每次请求到来时都会去数据库取一遍数据,这样可对数据库的数据做一个实时的更新 @app.route('/user') def user(): if request.method == "GET": #form = UserForm(data={'name':'alex','city':3}) form = UserForm() return render_template('user.html',form=form) if __name__ == '__main__': app.run()
login.html
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <title>Title</title> <meta name="viewport" content="width=device-width, initial-scale=1"> </head> <body> <form method="post" novalidate> <p>用户名:{{form.name}} {{form.name.errors[0]}}</p> <p>密码:{{form.pwd}} {{form.pwd.errors[0]}} </p> <p><input type="submit" value="提交" ></p> </form> </body> </html>
register.html
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <title>Title</title> <meta name="viewport" content="width=device-width, initial-scale=1"> </head> <body> <form method="post" novalidate> {% for field in form %} <p>{{field.label}}: {{field}} {{field.errors[0]}}</p> {% endfor %} <input type="submit" value="提交"> </form> </body> </html>
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <title>Title</title> <meta name="viewport" content="width=device-width, initial-scale=1"> </head> <body> <form method="post"> {% for field in form %} <p>{{field.label}}: {{field}} {{field.errors[0]}}</p> {% endfor %} <input type="submit" value="提交"> </form> </body> </html>
import pymysql from DBUtils.PooledDB import PooledDB, SharedDBConnection import pymysql 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='127.0.0.1', port=3306, user='root', password='2180736', database='s9day119', charset='utf8' ) def connect(type): conn = POOL.connection() cursor = conn.cursor(cursor=type) return conn,cursor def connect_close(conn,cursor): cursor.close() conn.close() def fetch_all(sql,args,type=pymysql.cursors.DictCursor): conn,cursor = connect(type) cursor.execute(sql, args) record_list = cursor.fetchall() connect_close(conn,cursor) return record_list def fetch_one(sql, args): conn, cursor = connect() cursor.execute(sql, args) result = cursor.fetchone() connect_close(conn, cursor) return result def insert(sql, args): conn, cursor = connect() row = cursor.execute(sql, args) conn.commit() connect_close(conn, cursor) return row
相关知识:
钩子函数:
class LoginForm(Form): name = simple.StringField( validators=[ validators.DataRequired(message='用户名不能为空.'), ], widget=widgets.TextInput(), render_kw={'placeholder':'请输入用户名'} ) pwd = simple.PasswordField( validators=[ validators.DataRequired(message='密码不能为空.'), ], render_kw={'placeholder':'请输入密码'} ) #钩子函数 def validate_name(self, field): """ 自定义name字段规则 :param field: :return: """ # 最开始初始化时,self.data中已经有所有的值 print('钩子函数获取的值',field.data) if not field.data.startswith('old'): raise validators.ValidationError("用户名必须以old开头") # 继续后续验证 # raise validators.StopValidation("用户名必须以old开头") # 不再继续后续验证