发现命令在 python unittest 中不起作用答案

【问题标题】：discover command not working in python unittest发现命令在 python unittest 中不起作用
【发布时间】：2015-07-15 13:12:25
【问题描述】：

我是 Python 新手。我正在尝试了解发现选项 python unittest 模块。我编写了两个测试脚本，其中包含相同的测试（复制相同的文件，以测试发现选项），其内容如下：。

testFirst.py

import unittest

class Test(unittest.TestCase):

    def testFailure(self):

        self.assertFalse(True)

    def testError(self):
        0 / 0

    def testPass(self):
        self.assertTrue(True)

import sys
sys.argv.append("-v")
unittest.main()

testSecond.py

import unittest

class Test(unittest.TestCase):

    def testFailure(self):

        self.assertFalse(True)

    def testError(self):
        0 / 0

    def testPass(self):
        self.assertTrue(True)

import sys
sys.argv.append("-v")
unittest.main()

输出

现在，当我从命令提示符运行“python -m unittest discover”命令时，我得到以下输出：

testError (testFirst.Test) ... ERROR
testFailure (testFirst.Test) ... FAIL
testPass (testFirst.Test) ... ok
testError (testSecond.Test) ... ERROR
testFailure (testSecond.Test) ... FAIL
testPass (testSecond.Test) ... ok

======================================================================
ERROR: testError (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
ERROR: testError (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
FAIL: testFailure (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

======================================================================
FAIL: testFailure (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

----------------------------------------------------------------------
Ran 6 tests in 0.000s

FAILED (failures=2, errors=2)
testError (testFirst.Test) ... ERROR
testFailure (testFirst.Test) ... FAIL
testPass (testFirst.Test) ... ok
testSecond (unittest.loader.ModuleImportFailure) ... ERROR

======================================================================
ERROR: testError (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
ERROR: testSecond (unittest.loader.ModuleImportFailure)
----------------------------------------------------------------------
ImportError: Failed to import test module: testSecond
Traceback (most recent call last):
  File "C:\Python27\lib\unittest\loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "C:\Python27\lib\unittest\loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "testSecond.py", line 28, in <module>
    unittest.main()
  File "C:\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Python27\lib\unittest\main.py", line 234, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: True


======================================================================
FAIL: testFailure (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

----------------------------------------------------------------------
Ran 4 tests in 0.000s

FAILED (failures=1, errors=2)
testError (testFirst.Test) ... ERROR
testFailure (testFirst.Test) ... FAIL
testPass (testFirst.Test) ... ok
testError (testSecond.Test) ... ERROR
testFailure (testSecond.Test) ... FAIL
testPass (testSecond.Test) ... ok

======================================================================
ERROR: testError (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
ERROR: testError (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
FAIL: testFailure (testFirst.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testFirst.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

======================================================================
FAIL: testFailure (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

----------------------------------------------------------------------
Ran 6 tests in 0.000s

FAILED (failures=2, errors=2)
testFirst (unittest.loader.ModuleImportFailure) ... ERROR
testError (testSecond.Test) ... ERROR
testFailure (testSecond.Test) ... FAIL
testPass (testSecond.Test) ... ok

======================================================================
ERROR: testFirst (unittest.loader.ModuleImportFailure)
----------------------------------------------------------------------
ImportError: Failed to import test module: testFirst
Traceback (most recent call last):
  File "C:\Python27\lib\unittest\loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "C:\Python27\lib\unittest\loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "testFirst.py", line 28, in <module>
    unittest.main()
  File "C:\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Python27\lib\unittest\main.py", line 234, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: True


======================================================================
ERROR: testError (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 21, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
FAIL: testFailure (testSecond.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testSecond.py", line 18, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

----------------------------------------------------------------------
Ran 4 tests in 0.000s

FAILED (failures=1, errors=2)
EE
======================================================================
ERROR: testFirst (unittest.loader.ModuleImportFailure)
----------------------------------------------------------------------
ImportError: Failed to import test module: testFirst
Traceback (most recent call last):
  File "C:\Python27\lib\unittest\loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "C:\Python27\lib\unittest\loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "testFirst.py", line 28, in <module>
    unittest.main()
  File "C:\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Python27\lib\unittest\main.py", line 234, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: True


======================================================================
ERROR: testSecond (unittest.loader.ModuleImportFailure)
----------------------------------------------------------------------
ImportError: Failed to import test module: testSecond
Traceback (most recent call last):
  File "C:\Python27\lib\unittest\loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "C:\Python27\lib\unittest\loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "testSecond.py", line 28, in <module>
    unittest.main()
  File "C:\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Python27\lib\unittest\main.py", line 234, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: True


----------------------------------------------------------------------
Ran 2 tests in 0.000s

FAILED (errors=2),

这给人的印象是测试执行了不止一次。为什么会这样？我做错了什么？

【问题讨论】：

您在每个模块的末尾调用unittest.main()。当您使用 discover 时，它会导入两个模块，从而运行其中的代码 → 执行单元测试，然后 unittest discover 调用执行所有单元测试。这就是他们运行两次的原因。
但是，为什么我会得到荒谬的测试计数，例如在 0.000 秒内运行 6 次测试，在 0.000 秒内运行 4 次测试，在 0.000 秒内运行 6 次测试，在 0.000 秒内运行 4 次测试，在 0.000 秒内运行 2 次测试0.000 秒。它清楚地表明它正在执行 22 个测试方法，而根据您的评论，即使它执行每个测试用例，总测试执行必须是 12，而不是 22，从哪里执行额外的 10 个方法？
下面给出的错误意味着：错误：testSecond (unittest.loader.ModuleImportFailure) ImportError: 无法导入测试模块：testSecond Traceback（最近一次调用）：文件“C:\Python27\lib\ unittest\loader.py”，第 254 行，在 _find_tests 模块 = self._get_module_from_name(name) 文件“C:\Python27\lib\unittest\loader.py”，第 232 行，在 _get_module_from_name __import__(name) 文件“testSecond.py "，第 28 行，在 unittest.main() 文件中 "C:\Python27\lib\unittest\main.py"，第 234 行，在 runTests sys.exit(not self.result.wasSuccessful()) SystemExit:是的

标签： python python-unittest

【解决方案1】：

如果您删除每个文件中的最后 3 行，而是在调用 unittest 时传递 详细选项 -v，它只会运行一次测试：

python -m unittest discover -v

结果：

testError (test_first.Test) ... ERROR
testFailure (test_first.Test) ... FAIL
testPass (test_first.Test) ... ok
testError (test_second.Test) ... ERROR
testFailure (test_second.Test) ... FAIL
testPass (test_second.Test) ... ok

======================================================================
ERROR: testError (test_first.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_first.py", line 9, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
ERROR: testError (test_second.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_second.py", line 9, in testError
    0 / 0
ZeroDivisionError: integer division or modulo by zero

======================================================================
FAIL: testFailure (test_first.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_first.py", line 6, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

======================================================================
FAIL: testFailure (test_second.Test)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_second.py", line 6, in testFailure
    self.assertFalse(True)
AssertionError: True is not false

----------------------------------------------------------------------
Ran 6 tests in 0.004s

FAILED (failures=2, errors=2)

【讨论】：