unittest 在导入时失败——缺少符号

Question

我是 Python、Python 命令行和 PyDev 的新手。 Fedora 20，Python 2.7.5，因为它出现在这个发行版上。我无法编写单元测试。已尝试导入 unittest 和 unittest2（如此处）。

from unittest2 import TestCase, main

def IsOdd( n ):
    return n % 2 == 1

class IsOddTests( TestCase ):
    def testOne( self ):
        self.failUnless( IsOdd( 1 ) )
    def testTwo( self ):
        self.failIf( IsOdd( 2 ) )

def main():
    main()

if __name__ == '__main__':
    main()

每次导入都有其问题。无论是从 Eclipse 中的 PyDev 控制台还是在命令行 shell 都会发生这种情况。我查看了 /usr/lib/python2.7/site-packages/* 下的内容，发现缺少的符号（TestCase 和 unit），但这对当前案例没有帮助。

/usr/bin/python 2.7.5 (default, Nov  3 2014, 14:26:24) 
[GCC 4.8.3 20140911 (Red Hat 4.8.3-7)]
PyDev console: starting.
>>> from unittest2 import TestCase, main
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python2.7/site-packages/unittest2/__init__.py", line 40, in <module>
    from unittest2.collector import collector
  File "/usr/lib/python2.7/site-packages/unittest2/collector.py", line 3, in <module>
    from unittest2.loader import defaultTestLoader
  File "/usr/lib/python2.7/site-packages/unittest2/loader.py", line 8, in <module>
    import unittest
  File "/home/russ/dev/python-workspace/max/src/unittest.py", line 11, in <module>
    from unittest2 import TestCase, main
  File "/usr/lib/python2.7/site-packages/unittest2/main.py", line 7, in <module>
    from unittest2 import loader, runner
  File "/usr/lib/python2.7/site-packages/unittest2/runner.py", line 7, in <module>
    from unittest2 import result
  File "/usr/lib/python2.7/site-packages/unittest2/result.py", line 26, in <module>
    class TestResult(unittest.TestResult):
AttributeError: 'module' object has no attribute 'TestResult'
>>> from unittest import TestCase, main
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/home/russ/dev/python-workspace/max/src/unittest.py", line 11, in <module>
    from unittest2 import TestCase, main
  File "/usr/lib/python2.7/site-packages/unittest2/__init__.py", line 40, in <module>
    from unittest2.collector import collector
  File "/usr/lib/python2.7/site-packages/unittest2/collector.py", line 3, in <module>
    from unittest2.loader import defaultTestLoader
  File "/usr/lib/python2.7/site-packages/unittest2/loader.py", line 12, in <module>
    from unittest2 import case, suite
  File "/usr/lib/python2.7/site-packages/unittest2/case.py", line 10, in <module>
    from unittest2 import result
  File "/usr/lib/python2.7/site-packages/unittest2/result.py", line 9, in <module>
    from unittest2 import util
ImportError: cannot import name util

Answer 1

我从未使用过 unittest2。鉴于它是一个内置的 python 并且经过严格审查，似乎使用普通的 unittest 可能会更好一些。我能够让它为我工作

from unittest import TestCase, main as unittest_main

def IsOdd( n ):
    return n % 2 == 1

class IsOddTests( TestCase ):
    def testOne( self ):
        self.failUnless( IsOdd( 1 ) )
    def testTwo( self ):
        self.failIf( IsOdd( 2 ) )

def main():
    unittest_main()

if __name__ == '__main__':
    main()

然后运行它

0 ✓ greg@MinasArnor ~/workspace $ python test.py 
..
----------------------------------------------------------------------
Ran 2 tests in 0.001s

OK

Answer 2

我在你的回溯中注意到了这一点：

File "/home/russ/dev/python-workspace/max/src/unittest.py", line 11, in <module>

还有这个：

class TestResult(unittest.TestResult):
AttributeError: 'module' object has no attribute 'TestResult'

重命名您的文件。您已将脚本命名为 unittest.py，因此 Python 正在查看 您的 单元测试脚本以用于类（如 TestResult），而不是像预期的那样查看内置单元测试模块。