Common form

Form Focus: 
    - The field 
        used to hold regular expression 
        ChoiceField ***** 
        MultipleChoiceField 
        CharField 
        IntegerField 
        DecimalField 
        DateField 
        DateTimeField 
        EmailField 
        GenericIPAddressField 
        FileField 
        
        RegexField 
    - HTML plug-in 
        is used to generate HTML tags 
        
    - special single or multiple select when, whether the data source in real time update? ? ? ? ? ***** 
        from app01 Import Models 
        class LoveForm (forms.Form): 
            . Price = fields.IntegerField () 
            user_id = fields.IntegerField ( 
                # = widgets.Select the widget (choices = [(0, 'Alex'), (. 1 'Liuhao Chen'), (2 'Yang')])
                widget=widgets.Select()
            )

            def __init__(self,*args,**kwargs):
                super(LoveForm,self).__init__(*args,**kwargs)
                self.fields['user_id'].widget.choices = models.UserInfo.objects.values_list('id','username')
                
        from django.forms.models import ModelChoiceField
        from django.forms.models import ModelChoiceField
        class LoveForm(forms.Form):
            price = fields.IntegerField()

            user_id2 = ModelChoiceField(
                queryset=models.UserInfo.objects.all(),
                to_field_name='id'
            )
        
        注意：依赖models中的str方法