[Tutor] A slight bug in IDLE

[Dave Angel]

On 07/13/2013 02:29 PM, Jim Mooney wrote:
> Steven D'Aprano <steve at pearwood.info>
>
> No, actually, it's the opposite of a gotcha. If a module expects to use
> truncated division, and *fails* to "from __future__ import division",
> that's what it needs to get. If your import would change what the other
> module sees, then you could change the behaviour of the other module (and
> probably break it) just by importing something from __future__.
> ====
>
>> \
>
>    Or worse, break it in a way that wasn't apparent until the plane fell out
> of the sky ;')
>
> Actually, I meant the reverse gotcha. Expecting float division when your
> imported module stuck to truncated. But either way it's good to know
> __future__ is not your usual sort of import.
>


You still don't understand.  If you write a module and I import it, then 
other imports BY ME don't affect your module. Whether it's a __future__ 
one or not.  My import affects my global namespace, not yours.  My 
compile-time switches affect my divide, not yours.  Same thing.

*Unless of course, we're in a case of recursive imports, or doing 
monkey-patching, or code-generation.

Same thing with the encoding line at the beginning of my module.  It 
affects how string literals and symbol names are to be decoded in my 
module, not in yours.  It's perfectly reasonable and safe to have some 
source files encoded in utf-8 and some in latin-1.  Pain in the neck for 
the text editor, but that's why the encoding string is flexible, so that 
editors like emacs can honor the same one.

-- 
DaveA