ValueError:在运行单元测试Django ModelViewSet时，没有足够的值来解包

Question

正在测试一个使用ModelViewSet检索数据的端点，并通过URL向其传递参数以获取数据，但在运行单元测试时出现此错误：

File "/Users/lutaayaidris/Documents/workspace/project_sample/project_sample/financing_settings/tests.py", line 195, in test_get_blocks
self.block_get_data), content_type='application/json')
File "/Users/lutaayaidris/Documents/workspace/project_sample/lib/python3.6/site-packages/rest_framework/test.py", line 286, in get
response = super().get(path, data=data, **extra)
File "/Users/lutaayaidris/Documents/workspace/project_sample/lib/python3.6/site-packages/rest_framework/test.py", line 194, in get
'QUERY_STRING': urlencode(data or {}, doseq=True),
File "/Users/lutaayaidris/Documents/workspace/project_sample/lib/python3.6/site-packages/django/utils/http.py", line 93, in urlencode
for key, value in query:
ValueError: not enough values to unpack (expected 2, got 1)

这就是我构建测试的方式，加上一些用于测试的伪数据：

class TemplateData:
"""Template Mock data."""

step_get_data = {
"param": "step"
}
block_get_data = {
"param": "block"
}
get_no_data = {
"param_": "block"
}

class TemplateViewTests(TestCase, TemplateData):
"""Template Tests (Block & Step)."""
def setUp(self):
"""
Initialize client,  Step and Block id and data created.
"""
self.client = APIClient()
self.block_id = 0
self.step_id = 0
self.create_block_step_data()
def create_block_step_data(self):
"""Create ProcessVersion, Step, & Block mock data."""
self.process_version = ProcessVersion.objects.create(
tag="TESTING_TAG",
is_process_template=False,
status="IN EDITING",
attr_map="TESTING_ATTR",
loan_options=None
)
self.step = Step.objects.create(
version=self.process_version,
is_process_template=True,
title="TESTING",
help_text="TESTING",
order=1,
slug="slug",
can_be_duplicated=False,
max_duplicated_number=2,
)
self.step_id = self.step.pk
self.block_id = Block.objects.create(
step=self.step,
is_process_template=True,
title="TESTING",
information_text="This is  testing "
"information",
order=1,
depending_field="depending_field",
visibility_value="visibility_value",
slug="slug",
can_be_duplicated=False,
max_duplicated_number=2,
).pk
self.process_version_1 = ProcessVersion.objects.create(
tag="TESTING_TAG",
is_process_template=False,
status="IN EDITING",
attr_map="TESTING_ATTR",
loan_options=None
)
self.step_1 = Step.objects.create(
version=self.process_version_1,
is_process_template=True,
title="TESTING",
help_text="TESTING",
order=1,
slug="slug",
can_be_duplicated=False,
max_duplicated_number=2,
)
self.block_1 = Block.objects.create(
step=self.step,
is_process_template=True,
title="TESTING",
information_text="This is  testing "
"information",
order=1,
depending_field="depending_field",
visibility_value="visibility_value",
slug="slug",
can_be_duplicated=False,
max_duplicated_number=2,
).pk
def test_get_blocks(self):
"""Test get list of Block. """
response = self.client.get(
"/api/v1/financing-settings/template/",
data=json.dumps(
self.block_get_data), content_type='application/json')
self.assertEqual(response.status_code, 200)
def test_get_steps(self):
"""Test get list of Step. """
response = self.client.get(
"/api/v1/financing-settings/template/",
data=json.dumps(
self.block_get_data),
content_type='application/json')
self.assertEqual(response.status_code, 200)
def test_no_step_or_block(self):
"""Test get no list of Step or Block. """
response = self.client.get(
"/api/v1/financing-settings/template/",
data=json.dumps(
self.block_get_data),
content_type='application/json')
self.assertEqual(response.status_code, 204)

正如你在上面看到的，这些都是我的测试，我已经设置了数据，现在我想取回数据，但由于上面的异常，我不能。

最后，在我的端点实现中，我使用Viewset来处理这个问题，下面是代码：

class TemplateView(ModelViewSet):
"""ViewSet for Saving Block/ Step template."""

def list(self, request, *args, **kwargs):
"""Get list of Block/Steps with is_process_template is equal to True."""
param = request.data['param']
if param == "block":
_block = Block.objects.filter(is_process_template=True).values()
return JsonResponse({"data": list(_block)}, safe=False, status=200)
elif param == "step":
_step = Step.objects.filter(is_process_template=True)
return JsonResponse({"data": list(_step)}, safe=False, status=200)
return Response(status=status.HTTP_204_NO_CONTENT)

是什么导致了这种情况，在我的理解中，我觉得一切都应该运转起来。

Answer 1

函数Client.get期望一个字典作为数据参数，并尝试使用函数urlencode在url中对其进行编码。你可以这样做：

from django.test import Client
c = Client()
block_get_data = {
"param": "block"
}
c.get('path', block_get_data)

block_get_data将在url中作为"param=block"发送

如果你想在GET方法中发送JSON格式的数据，你可以使用Client.generic函数如下：

from django.test import Client
import json
c = Client()
block_get_data = {
"param": "block"
}
c.generic('GET', 'path', json.dumps(block_get_data), 'application/json')

Answer 2

您正面临此错误，因为此dict

block_get_data = {
"param": "block"
}

你正试图以这种方式使用

for key,val in block_get_data

它会产生类似的错误

for key,val in block_get_data:
ValueError: too many values to unpack (expected 2)

如果您使用.items()方法通过dict循环，它将被解决。

for key,val in block_get_data.items():

我认为将参数传递为self.block_get_data.items()可以解决您的问题。