python - 我如何使这个测试通过？

Question

我正在尝试测试 __repr__ 的返回类型。它不是一个字符串，那它是什么？这里发生了什么？

import unittest
class MyClass(unittest.TestCase):
    class Dog(object):
            def __init__(self, initial_name):
                self._name = initial_name

            def get_self(self):
                return self

            def __repr__(self):
                return "Dog named '" + self._name + "'"

    def runTest(self):
        fido = self.Dog("Fido")
        self.assertEqual("Dog named 'Fido'", fido.get_self()) #Fails!

test=MyClass("runTest")
runner=unittest.TextTestRunner()
runner.run(test)

运行这个给出:

FAIL: runTest (__main__.MyClass)
----------------------------------------------------------------------
Traceback (most recent call last):
   File "/home/xxxxx/fido.py", line 15, in runTest
     self.assertEqual("Dog named 'Fido'", fido.get_self())
   AssertionError: "Dog named 'Fido'" != Dog named 'Fido'

 ----------------------------------------------------------------------
 Ran 1 test in 0.006s

 FAILED (failures=1)

我怎样才能通过这个测试？

Answer 1

self.assertEqual("Dog named 'Fido'", repr(fido.get_self()))

或者只是

self.assertEqual("Dog named 'Fido'", repr(fido))

否则 assertEqual 会正确地告诉您字符串不等于对象。当它呈现错误消息时，它在对象上使用了 repr，所以错误看起来有点困惑