Python unit_test load_tests函數失敗

Question

我打電話給unittest load_tests來建立一個測試套件，但失敗並出現錯誤。

import unittest

def load_tests(loader, tests, pattern):
    print 'load_tests called'
    f = ['a','b']  # data.csv contains three lines: "a\nb\nc"
    for line in f:
        tc = Foo()
        tc.setup(line)
        tests.addTest(tc)
    return tests

class Foo(unittest.TestCase):
    def setup(self,bar):
        print "Foo.setup()"
        print dir(self)
        self.bar = bar


    def runTest(self):
        print 'running'
        print self.bar

unittest.main()

錯誤

load_tests called
Foo.setup()
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_addSkip', '_baseAssertEqual', '_classSetupFailed', '_cleanups', '_deprecate', '_diffThreshold', '_formatMessage', '_getAssertEqualityFunc', '_resultForDoCleanups', '_testMethodDoc', '_testMethodName', '_truncateMessage', '_type_equality_funcs', 'addCleanup', 'addTypeEqualityFunc', 'assertAlmostEqual', 'assertAlmostEquals', 'assertDictContainsSubset', 'assertDictEqual', 'assertEqual', 'assertEquals', 'assertFalse', 'assertGreater', 'assertGreaterEqual', 'assertIn', 'assertIs', 'assertIsInstance', 'assertIsNone', 'assertIsNot', 'assertIsNotNone', 'assertItemsEqual', 'assertLess', 'assertLessEqual', 'assertListEqual', 'assertMultiLineEqual', 'assertNotAlmostEqual', 'assertNotAlmostEquals', 'assertNotEqual', 'assertNotEquals', 'assertNotIn', 'assertNotIsInstance', 'assertNotRegexpMatches', 'assertRaises', 'assertRaisesRegexp', 'assertRegexpMatches', 'assertSequenceEqual', 'assertSetEqual', 'assertTrue', 'assertTupleEqual', 'assert_', 'countTestCases', 'debug', 'defaultTestResult', 'doCleanups', 'fail', 'failIf', 'failIfAlmostEqual', 'failIfEqual', 'failUnless', 'failUnlessAlmostEqual', 'failUnlessEqual', 'failUnlessRaises', 'failureException', 'id', 'longMessage', 'maxDiff', 'run', 'runTest', 'setUp', 'setUpClass', 'setup', 'shortDescription', 'skipTest', 'tearDown', 'tearDownClass']
Foo.setup()
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_addSkip', '_baseAssertEqual', '_classSetupFailed', '_cleanups', '_deprecate', '_diffThreshold', '_formatMessage', '_getAssertEqualityFunc', '_resultForDoCleanups', '_testMethodDoc', '_testMethodName', '_truncateMessage', '_type_equality_funcs', 'addCleanup', 'addTypeEqualityFunc', 'assertAlmostEqual', 'assertAlmostEquals', 'assertDictContainsSubset', 'assertDictEqual', 'assertEqual', 'assertEquals', 'assertFalse', 'assertGreater', 'assertGreaterEqual', 'assertIn', 'assertIs', 'assertIsInstance', 'assertIsNone', 'assertIsNot', 'assertIsNotNone', 'assertItemsEqual', 'assertLess', 'assertLessEqual', 'assertListEqual', 'assertMultiLineEqual', 'assertNotAlmostEqual', 'assertNotAlmostEquals', 'assertNotEqual', 'assertNotEquals', 'assertNotIn', 'assertNotIsInstance', 'assertNotRegexpMatches', 'assertRaises', 'assertRaisesRegexp', 'assertRegexpMatches', 'assertSequenceEqual', 'assertSetEqual', 'assertTrue', 'assertTupleEqual', 'assert_', 'countTestCases', 'debug', 'defaultTestResult', 'doCleanups', 'fail', 'failIf', 'failIfAlmostEqual', 'failIfEqual', 'failUnless', 'failUnlessAlmostEqual', 'failUnlessEqual', 'failUnlessRaises', 'failureException', 'id', 'longMessage', 'maxDiff', 'run', 'runTest', 'setUp', 'setUpClass', 'setup', 'shortDescription', 'skipTest', 'tearDown', 'tearDownClass']
running
Erunning
a
.running
b
.
======================================================================
ERROR: runTest (__main__.Foo)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test.py", line 21, in runTest
    print self.bar
AttributeError: 'Foo' object has no attribute 'bar'

----------------------------------------------------------------------
Ran 3 tests in 0.016s

FAILED (errors=1)

Answer 1

一個更詳細的問題會有所幫助。 我不確定您要使用此代碼解決什么問題，但是我將嘗試解釋錯誤的原因。

load_tests函數中的tests參數是unittest.TestSuite對象，該對象已經包含一個測試用例。 該測試用例是當您調用unittest.main()時unittest查找和創建的Foo對象，因為Foo是unittest.TestCase的子類。 如果在load_tests的開頭print tests ，則可以看到此load_tests 。

如果只希望由load_tests創建兩個測試用例，那么load_tests應該創建並返回一個新的套件：

def load_tests(loader, tests, pattern):
    print 'load_tests called'
    suite = unittest.TestSuite()
    f = ['a','b']  # data.csv contains three lines: "a\nb\nc"
    for line in f:
        tc = Foo()
        tc.setup(line)
        suite.addTest(tc)
    return suite

輸出量

python foo.py 
load_tests called
Foo.setup()
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_addSkip', '_baseAssertEqual', '_classSetupFailed', '_cleanups', '_deprecate', '_diffThreshold', '_formatMessage', '_getAssertEqualityFunc', '_resultForDoCleanups', '_testMethodDoc', '_testMethodName', '_truncateMessage', '_type_equality_funcs', 'addCleanup', 'addTypeEqualityFunc', 'assertAlmostEqual', 'assertAlmostEquals', 'assertDictContainsSubset', 'assertDictEqual', 'assertEqual', 'assertEquals', 'assertFalse', 'assertGreater', 'assertGreaterEqual', 'assertIn', 'assertIs', 'assertIsInstance', 'assertIsNone', 'assertIsNot', 'assertIsNotNone', 'assertItemsEqual', 'assertLess', 'assertLessEqual', 'assertListEqual', 'assertMultiLineEqual', 'assertNotAlmostEqual', 'assertNotAlmostEquals', 'assertNotEqual', 'assertNotEquals', 'assertNotIn', 'assertNotIsInstance', 'assertNotRegexpMatches', 'assertRaises', 'assertRaisesRegexp', 'assertRegexpMatches', 'assertSequenceEqual', 'assertSetEqual', 'assertTrue', 'assertTupleEqual', 'assert_', 'countTestCases', 'debug', 'defaultTestResult', 'doCleanups', 'fail', 'failIf', 'failIfAlmostEqual', 'failIfEqual', 'failUnless', 'failUnlessAlmostEqual', 'failUnlessEqual', 'failUnlessRaises', 'failureException', 'id', 'longMessage', 'maxDiff', 'run', 'runTest', 'setUp', 'setUpClass', 'setup', 'shortDescription', 'skipTest', 'tearDown', 'tearDownClass']
Foo.setup()
['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_addSkip', '_baseAssertEqual', '_classSetupFailed', '_cleanups', '_deprecate', '_diffThreshold', '_formatMessage', '_getAssertEqualityFunc', '_resultForDoCleanups', '_testMethodDoc', '_testMethodName', '_truncateMessage', '_type_equality_funcs', 'addCleanup', 'addTypeEqualityFunc', 'assertAlmostEqual', 'assertAlmostEquals', 'assertDictContainsSubset', 'assertDictEqual', 'assertEqual', 'assertEquals', 'assertFalse', 'assertGreater', 'assertGreaterEqual', 'assertIn', 'assertIs', 'assertIsInstance', 'assertIsNone', 'assertIsNot', 'assertIsNotNone', 'assertItemsEqual', 'assertLess', 'assertLessEqual', 'assertListEqual', 'assertMultiLineEqual', 'assertNotAlmostEqual', 'assertNotAlmostEquals', 'assertNotEqual', 'assertNotEquals', 'assertNotIn', 'assertNotIsInstance', 'assertNotRegexpMatches', 'assertRaises', 'assertRaisesRegexp', 'assertRegexpMatches', 'assertSequenceEqual', 'assertSetEqual', 'assertTrue', 'assertTupleEqual', 'assert_', 'countTestCases', 'debug', 'defaultTestResult', 'doCleanups', 'fail', 'failIf', 'failIfAlmostEqual', 'failIfEqual', 'failUnless', 'failUnlessAlmostEqual', 'failUnlessEqual', 'failUnlessRaises', 'failureException', 'id', 'longMessage', 'maxDiff', 'run', 'runTest', 'setUp', 'setUpClass', 'setup', 'shortDescription', 'skipTest', 'tearDown', 'tearDownClass']
running
a
.running
b
.
----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK