textwrap.dedent() drops tabs - bug or feature?

[Steven Bethard]

Peter Hansen wrote:
> Steven Bethard wrote:
> 
>> Note that even though the tabs are internal, they are still removed by 
>> textwrap.dedent().  The documentation[1] says:
> 
> ...
> 
>> So it looks to me like even if this is a "feature" it is undocumented. 
>> I'm planning on filing a bug report, but I wanted to check here first 
>> in case I'm just smoking something.
> 
> While I wouldn't say it's obvious, I believe it is (indirectly?) 
> documented and deliberate.
> 
> Search for this in the docs:
> """
> expand_tabs
>     (default: True) If true, then all tab characters in text will be 
> expanded to spaces using the expandtabs() method of text.
> """

Thanks for double-checking this for me.  I looked at expand_tabs, and 
it's part of the definition of the TextWrapper class, which is not 
actually used by textwrap.dedent().  So I think the textwrap.dedent() 
expanding-of-tabs behavior is still basically undocumented.

I looked at the source code, and the culprit is the first line of the 
function definition:

     lines = text.expandtabs().split('\n')

I filed a bug_ report, but left the Category unassigned so that someone 
else can decide whether it's a doc bug or a code bug.

STeVe

.. _bug: http://python.org/sf/1361643