当正常输出和异常混合在一起时，Doctest 失败？答案

【问题标题】：Doctest fails when normal output and exception mixed together?当正常输出和异常混合在一起时，Doctest 失败？
【发布时间】：2016-12-16 20:59:51
【问题描述】：

doctest 是否支持将输出和异常混合在一起？

一个例子是：

>>> def foo():
...    print 'hello world!'
>>> foo()
hello world!
>>> def bar():
...     raise Exception()
>>> bar()
Traceback (most recent call last):
    ...
Exception

>>> def foo_bar():
...     foo()
...     bar()
>>> foo_bar()
hello world!
Traceback (most recent call last):
    ...
Exception

我希望所有三个案例都应该成功，但只有两个成功，请参阅

$ python -m doctest -v /tmp/1.py
Trying:
    def foo():
       print 'hello world!'
Expecting nothing
ok
Trying:
    foo()
Expecting:
    hello world!
ok
Trying:
    def bar():
        raise Exception()
Expecting nothing
ok
Trying:
    bar()
Expecting:
    Traceback (most recent call last):
        ...
    Exception
ok
Trying:
    def foo_bar():
        foo()
        bar()
Expecting nothing
ok
Trying:
    foo_bar()
Expecting:
    hello world!
    Traceback (most recent call last):
        ...
    Exception
**********************************************************************
File "/tmp/1.py", line 16, in 1
Failed example:
    foo_bar()
Exception raised:
    Traceback (most recent call last):
      File "/usr/lib/python2.7/doctest.py", line 1315, in __run
        compileflags, 1) in test.globs
      File "<doctest 1[5]>", line 1, in <module>
        foo_bar()
      File "<doctest 1[4]>", line 3, in foo_bar
        bar()
      File "<doctest 1[2]>", line 2, in bar
        raise Exception()
    Exception
**********************************************************************
1 items had failures:
   1 of   6 in 1
6 tests in 1 items.
5 passed and 1 failed.
***Test Failed*** 1 failures.

【问题讨论】：

标签： python testing doctest

【解决方案1】：

docs 说你不能这样做：

不支持同时包含预期输出和异常的示例。试图猜测一个结束和另一个开始的地方太容易出错，这也会使测试变得混乱。

【讨论】：

【解决方案2】：

常规输出和回溯不能混合，因为它们只是无法区分的文本。但是，您可以包装块，捕获您期望的异常：

>>> try:
...     foo_bar()
... except TheSpecificExceptionYouWant:
...     pass
... else:
...     raise AssertionError('Should have raised an exception')
hello world!

【讨论】：