获取项的id而不是值，django表单

from django import forms

CHOICES = (
    ('1', '选项1'),
    ('2', '选项2'),
    ('3', '选项3'),
)

class MyForm(forms.Form):
    my_field = forms.ChoiceField(choices=CHOICES)

def my_view(request):
    if request.method == 'POST':
        form = MyForm(request.POST)
        if form.is_valid():
            selected_id = form.cleaned_data['my_field']
            # 根据选项的id进行相应的处理
            return HttpResponse(f"选择的id是：{selected_id}")
    else:
        form = MyForm()
    
    return render(request, 'my_template.html', {'form': form})