App Engine 单元测试：ImportError：开始目录不可导入

我正在尝试使用 Google App Engine 学习单元测试，方法是使用他们在 Python 本地单元测试页面上放置的确切代码（https://cloud.google.com/appengine/docs/python/tools/localunittesting https://cloud.google.com/appengine/docs/python/tools/localunittesting）。但我无法弄清楚这个错误：

ImportError: Start directory is not importable: 'testmem.py' 

我只是使用他们的简单测试框架作为 testrunner.py 以及他们的数据存储和 Memcache 测试在一个名为 testmem.py 的文件中。我从项目根目录调用测试：

<me>$ python testrunner.py ~/google_appengine testmem.py

据我所知，这与用法相匹配：%prog SDK_PATH TEST_PATH。

我的文件结构是：

__init__.py
app.yaml
testrunner.py
testmem.py
helloworld.py

谁能告诉我我在这里做错了什么？提前致谢。

完整的错误消息：

Traceback (most recent call last):
  File "testrunner.py", line 30, in <module>
    main(SDK_PATH, TEST_PATH)
  File "testrunner.py", line 17, in main
    suite = unittest.loader.TestLoader().discover(test_path)
  File "/usr/lib/python2.7/unittest/loader.py", line 204, in discover
    raise ImportError('Start directory is not importable: %r' % start_dir)
ImportError: Start directory is not importable: 'testmem.py'

测试运行器.py：

#!/usr/bin/python
import optparse
import sys
import unittest

USAGE = """%prog SDK_PATH TEST_PATH
Run unit tests for App Engine apps.

SDK_PATH    Path to the SDK installation
TEST_PATH   Path to package containing test modules"""


def main(sdk_path, test_path):
    sys.path.insert(0, sdk_path)
    import dev_appserver
    dev_appserver.fix_sys_path()
    suite = unittest.loader.TestLoader().discover(test_path)
    unittest.TextTestRunner(verbosity=2).run(suite)


if __name__ == '__main__':
    parser = optparse.OptionParser(USAGE)
    options, args = parser.parse_args()
    if len(args) != 2:
        print 'Error: Exactly 2 arguments required.'
        parser.print_help()
        sys.exit(1)
    SDK_PATH = args[0]
    TEST_PATH = args[1]
    main(SDK_PATH, TEST_PATH)

测试内存.py：

import unittest
from google.appengine.api import memcache
from google.appengine.ext import db
from google.appengine.ext import testbed

class TestModel(db.Model):
    """A model class used for testing."""
    number = db.IntegerProperty(default=42)
    text = db.StringProperty()

class TestEntityGroupRoot(db.Model):
    """Entity group root"""
    pass

def GetEntityViaMemcache(entity_key):
    """Get entity from memcache if available, from datastore if not."""
    entity = memcache.get(entity_key)  # @UndefinedVariable
    if entity is not None:
        return entity
    entity = TestModel.get(entity_key)
    if entity is not None:
        memcache.set(entity_key, entity)  # @UndefinedVariable
    return entity

class DemoTestCase(unittest.TestCase):

    def setUp(self):    
        # First, create an instance of the Testbed class.
        self.testbed = testbed.Testbed()
        # Then activate the testbed, which prepares the service stubs for use.
        self.testbed.activate()
        # Next, declare which service stubs you want to use.
        self.testbed.init_datastore_v3_stub()
        self.testbed.init_memcache_stub()

    def tearDown(self):
        self.testbed.deactivate()

    def testInsertEntity(self):
        TestModel().put()
        self.assertEqual(1, len(TestModel.all().fetch(2)))

    def testFilterByNumber(self):
        root = TestEntityGroupRoot(key_name="root")
        TestModel(parent=root.key()).put()
        TestModel(number=17, parent=root.key()).put()
        query = TestModel.all().ancestor(root.key()).filter('number =', 42)
        results = query.fetch(2)
        self.assertEqual(1, len(results))
        self.assertEqual(42, results[0].number)

    def testGetEntityViaMemcache(self):
        entity_key = str(TestModel(number=18).put())
        retrieved_entity = GetEntityViaMemcache(entity_key)
        self.assertNotEqual(None, retrieved_entity)
        self.assertEqual(18, retrieved_entity.number)


if __name__ == '__main__':
    unittest.main()

这里，“测试路径”应该是包含要运行的测试的目录，而不是单个模块的路径。尝试只使用.作为目录（假设您从顶级项目/应用程序目录运行它）并查看是否有帮助。

我的团队将测试保存在与源代码不同的目录中，因此我们将使用测试目录的路径作为第二个参数。