Can python doctest ignore some output lines?

Question

I\'d like to write a doctest like this:

\"\"\"
>>> print a.string()
          foo : a
          bar : b
         date : 

        

Answer 1

Responding to questions about "how can we ignore the whole line": yes, the fact that "..." also looks like a continuation like makes it hard to ignore the entire output. You can use "#doctest: +SKIP" if you just want to skip the example entirely, but that won't work if you are relying on its side-effects. If you really need to do this, I suppose you could monkey-patch the doctest module itself, though I wouldn't particularly recommend it:

>>> import doctest
>>> doctest.ELLIPSIS_MARKER = '-etc-'
>>> print 12 # doctest: +ELLIPSIS
-etc-

(this test passes.)

Or you could temporarily suppress stdout and/or stderr:

>>> # Suppress stdout
>>> import sys
>>> class DevNull:
...     def noop(*args, **kwargs): pass
...     close = write = flush = writelines = noop
>>> sys.stdout = DevNull()
>>> # Run a test and ignore output (but we need its side effects)
>>> print 12 # NOTE: stdout is suppressed!
>>> # Restore stdout
>>> sys.stdout = sys.__stdout__

(this test also passes.)