ValueError: not enough values to unpack (expected 2, got 1)

the following is my code

views.py

from django.shortcuts import render
from .forms import MedicineForm
from .models import Medicine

def index(request):
    all_medicine = Medicine.objects.order_by('id')
    return render(request, 'medicine/index.html', {'all_medicine': all_medicine})

def add(request):
if request.method == 'POST':
    form = MedicineForm(request.POST)
    if form.is_valid():
        new = Medicine()
        new.name = form.cleaned_data['药品名称']
        new.price = form.cleaned_data['药品价格']
        new.number = form.cleaned_data['药品编号']
        new.sort = form.cleaned_data['药品分类']
        new.unit = form.cleaned_data['计价单位']
        new.save()
        return render(request, 'medicine/index.html')
else:
    form = MedicineForm()
return render(request, 'medicine/add.html', {'form': form},)

forms.py

from django import forms


class MedicineForm(forms.Form):
    药品编号 = forms.IntegerField()
    药品名称 = forms.CharField(max_length=100)
    药品价格 = forms.IntegerField()
    jj_choice = {
        '瓶': '瓶',
        '包': '包',
        '盒': '盒',
    }
    计价单位 = forms.ChoiceField(
        choices=jj_choice
    )
    药品分类 = forms.CharField(max_length=100)

add.html:

{% extends 'polls/index.html' %}


{% block medicine_form %}
<form action="http://localhost:8000/medicine/add/" method="post">
    {% csrf_token %}
    {{ form }}
    <input type="submit" value="添加药品" />
</form>


{% endblock %}

traceback:

File "E:\p\lib\site-packages\django\core\handlers\exception.py" in inner
39. response = get_response(request)

File "E:\p\lib\site-packages\django\core\handlers\base.py" in _get_response
187. response = self.process_exception_by_middleware(e, request)

File "E:\p\lib\site-packages\django\core\handlers\base.py" in _get_response
185. response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "F:\ddjj\x\mysite\medicine\views.py" in add
25. return render(request, 'medicine/add.html', {'form': form},)

File "E:\p\lib\site-packages\django\shortcuts.py" in render
30. content = loader.render_to_string(template_name, context, request, using=using)

File "E:\p\lib\site-packages\django\template\loader.py" in render_to_string
68. return template.render(context, request)

File "E:\p\lib\site-packages\django\template\backends\django.py" in render
66. return self.template.render(context)

File "E:\p\lib\site-packages\django\template\base.py" in render
208. return self._render(context)

File "E:\p\lib\site-packages\django\template\base.py" in _render
199. return self.nodelist.render(context)

File "E:\p\lib\site-packages\django\template\base.py" in render
994. bit = node.render_annotated(context)

File "E:\p\lib\site-packages\django\template\base.py" in render_annotated
961. return self.render(context)

File "E:\p\lib\site-packages\django\template\loader_tags.py" in render
174. return compiled_parent._render(context)

File "E:\p\lib\site-packages\django\template\base.py" in _render
199. return self.nodelist.render(context)

File "E:\p\lib\site-packages\django\template\base.py" in render
994. bit = node.render_annotated(context)

File "E:\p\lib\site-packages\django\template\base.py" in render_annotated
961. return self.render(context)

File "E:\p\lib\site-packages\django\template\loader_tags.py" in render
70. result = block.nodelist.render(context)

File "E:\p\lib\site-packages\django\template\base.py" in render
994. bit = node.render_annotated(context)

File "E:\p\lib\site-packages\django\template\base.py" in render_annotated
961. return self.render(context)

File "E:\p\lib\site-packages\django\template\base.py" in render
1050. return render_value_in_context(output, context)

File "E:\p\lib\site-packages\django\template\base.py" in render_value_in_context
1028. value = force_text(value)

File "E:\p\lib\site-packages\django\utils\encoding.py" in force_text
76. s = six.text_type(s)

File "E:\p\lib\site-packages\django\utils\html.py" in
391. klass.str = lambda self: mark_safe(klass_str(self))

File "E:\p\lib\site-packages\django\forms\forms.py" in str
123. return self.as_table()

File "E:\p\lib\site-packages\django\forms\forms.py" in as_table
271. errors_on_separate_row=False)

File "E:\p\lib\site-packages\django\forms\forms.py" in _html_output
226. 'field': six.text_type(bf),

File "E:\p\lib\site-packages\django\utils\html.py" in
391. klass.str = lambda self: mark_safe(klass_str(self))

File "E:\p\lib\site-packages\django\forms\boundfield.py" in str
43. return self.as_widget()

File "E:\p\lib\site-packages\django\forms\boundfield.py" in as_widget
101. return force_text(widget.render(name, self.value(), attrs=attrs))

File "E:\p\lib\site-packages\django\forms\widgets.py" in render
537. options = self.render_options([value])

File "E:\p\lib\site-packages\django\forms\widgets.py" in render_options
560. for option_value, option_label in self.choices:

Exception Type: ValueError at /medicine/add/
Exception Value: not enough values to unpack (expected 2, got 1)