为什么我在使用Python3.4&#39；的‘unitest’库时出现AttributeError？

问题描述

下面是我的代码：

import unittest

class Primes:
    @staticmethod
    def first(n):
    <python code here>

class Test(unittest.TestCase):
    def __init__(self):
        pass
    def assert_equals(self, l, m):
        self.assertEqual(l, m)

Test = Test()
Test.assert_equals(Primes.first(1), [2])

每当我运行代码时，都会收到以下错误：

Traceback (most recent call last):
  File "firstNPrimes.py", line 37, in <module>
    Test.assert_equals(Primes.first(1), [2])
  File "firstNPrimes.py", line 34, in assert_equals
    self.assertEqual(l, m)
  File "/usr/lib/python3.4/unittest/case.py", line 796, in assertEqual
    assertion_func = self._getAssertEqualityFunc(first, second)
  File "/usr/lib/python3.4/unittest/case.py", line 777, in _getAssertEqualityFunc
    asserter = self._type_equality_funcs.get(type(first))
AttributeError: 'Test' object has no attribute '_type_equality_funcs'

我不明白这里有什么问题。

---

解决方案

您收到该错误是因为您没有正确使用unittest。根据the example in the docs，您的测试应如下所示：

import unittest

class TestPrimes(unittest.TestCase):

    def test_singlePrime_returnsListContainingTwo(self):
        self.assertEqual(Primes.first(1), [2])

    def test_whateverCase_expectedOutcome(self):
        self.assertEqual(Primes.first(...), ...)

if __name__ == '__main__':  # optional, but makes import and reuse easier
    unittest.main()

您不能只自己实例化测试用例类并调用方法，这会跳过所有测试发现和设置。