为ModelForm自动生成的input框添加BootStrap样式

from django import forms

class BootStrapModelForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # 循环找到所有的插件，添加class = "form-control"样式
        for name, field in self.fields.items():
            #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 UserModelForm(BootStrapModelForm):
    # 设置更多校验，用户名至少为三个字符
    name = forms.CharField(min_length=3, label="用户名")

    class Meta:
        model = models.UserInfo
        fields = ["name", "password", "age", "acount", "creata_time", "gender", "depart"]