如何在 doctest 变量中包含换行符？

Question

我想将输入到文档测试的文本分成新行。这是一个最小的例子：

import doctest

def example1():
    """
    >>> txt = '\\n'.join(['abcd', 'efg'])
    """

    return '\\n'.join(['abcd', 'efg'])


def example2():
    """
    >>> txt = '\\n'.join(['abcd',
    'efg'])
    """

    return '\\n'.join(['abcd',
    'efg'])

doctest.testmod()

结果是：

File "example.py", line 16, in __main__.example2
Failed example:
    txt = '\n'.join(['abcd',
Exception raised:
    Traceback (most recent call last):
      File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/doctest.py", line 1329, in __run
        compileflags, 1), test.globs)
      File "<doctest __main__.example2[0]>", line 1
        txt = '\n'.join(['abcd',
                               ^
    SyntaxError: unexpected EOF while parsing

数组内换行的语法适用于函数体，但不适用于文档测试。如何将文档测试中的长字符串排列成新行？

Answer 1

文档测试需要显式换行符转义。所以添加一个反斜杠：

"""
>>> txt = '\\n'.join(['abcd', \
'efg'])
"""