ModelForm基类：添加bootstrap新式

from django import forms

class BootStrapModelForm(forms.ModelForm):
# 不使用bootstrap样式的字段
bootstrap_exclude_fields=[]
def init(self, args, **kwargs):
super().init(args, **kwargs)
# 循环ModelForm中的所有字段，给每个字段的插件设置
for name, field in self.fields.items():
if name in self.bootstrap_exclude_fields:
continue
# 字段中有属性，保留原来的属性，没有属性，才增加。
if field.widget.attrs:
field.widget.attrs['class'] = 'form-control'
field.widget.attrs['placeholder'] = field.label
else:
field.widget.attrs = {
'class': 'form-control',
'placeholder': field.label
}

class BootStrapModelForm(BootStrap, forms.ModelForm):
pass

class BootStrapForm(BootStrap, forms.Form):
pass