# ===========方式一================

class Foo(object):

    user = 123

    def __init__(self):

        self.name = 123

        self.age = 456

    def aaa(self):

        self.name = 'sd'

obj = Foo()

# print(obj.__dict__)  #获取对象属性

# print(Foo.__dict__) #获取类里面的所有属性以及方法等

# ===============方式二==================

class Foo2(object):

    A  = 123

    def __init__(self):

        self.name = 'haiyan'

        self.age = 22

        # print(self.__class__.field)  #获取当前类的

    def __new__(cls, *args, **kwargs):

        print(cls.__dict__)

        return object.__new__(cls)

Foo2()

import re

import copy

class ValidateError(Exception) :

    '''自定义异常'''

    def __init__(self,detail):

        self.detail = detail

# ===========自定义插件===============

class TextInput(object):

    def __str__(self):

        return '<input type="text">'

class EmailInput(object):

    def __str__(self):

        return '<input type="email">'

# ============字段：内部包含正则用于验证======================

class Field(object):

    def __init__(self,required=True,error_message=None, widgets= None):

        self.required = required

        self.error_message = error_message

        if not widgets:

            self.widgets = TextInput()  #设置默认

        else:

            self.widgets = widgets

    def __str__(self):

        # return self.widgets

        return str(self.widgets)  #将对象转成字符串

class CharField(Field):

    def valid(self,val):

        if self.required:

            if not val:

                msg = self.error_message['required']

                raise ValidateError(msg)  #调用自定义的异常

        return val

class EmailField(Field):

    ERG = "^\w+@\w+$"

    def valid(self,val):

        if self.required:

            if not val:

                msg = self.error_message['required']

                raise ValidateError(msg)

        # print(val, type(val))

        result = re.match(self.ERG,val)

        if not result:

            msg = self.error_message.get('invalid','格式错误')

            raise ValidateError(msg)

        return val

# ==========================

class Form(object):

    def __init__(self,data):

        # print(UserForm.__dict__)#获取派生类中的所有静态字段

        # print(self.__class__.__dict__)  #静态动态的获取类中的所有静态字段

        self.data = data

        self.fields = copy.deepcopy(self.__class__.declare_field)  #获取字段

        self.clean_data = {}

        self.errors = {}

    def __new__(cls, *args, **kwargs):  #在__new__里面也可以获取类中的所有静态字段

        declare_field = {}

        for field_name , field in cls.__dict__.items():

            # print(field_name,field)

            if isinstance(field,Field):

                declare_field[field_name] = field

        cls.declare_field = declare_field

        return object.__new__(cls)  #创建对象

    def is_valid(self):

        #用户提交的数据

        # self.data  #{'username':"zzz","pwd":18}

        # self.fields #{'username': CharField(),"pwd": EmailField()}

        for field_name , field in self.fields.items():

            try:

                input_val = self.data.get(field_name)

                # print("---------------",field_name,input_val)

                val = field.valid(input_val)  #内置的验证规则自己去验证

                method = getattr(self,"clean_%s"%field_name,None)  #默认为None

                if method:

                    val = method(val)

                self.clean_data[field_name] = val

            except ValidateError as e:

                self.errors[field_name] = e.detail

        return len(self.errors) ==0 #根据错误的返回，如果没有错误返回True，有错误返回False

    def  __iter__(self):  ##########自定义生成标签3

        return iter(self.fields.values())  #返回的是一个迭代器

# =======================

class UserForm(Form):

    username = CharField(error_message={'required': '用户名不能为空'}, widgets=TextInput())

    # email = EmailField(error_message={'required': '密码不能为空', 'invalid': '邮箱格式错误'}, widgets=EmailInput())

obj = UserForm(data={'username':"haiyan","email":"dsfsgd"})

if obj.is_valid():

    print(obj.clean_data)

else:

    print(obj.errors)