[Tutor] What would be good use cases for the enum module?

[Steven D'Aprano]

On Sun, Apr 09, 2017 at 10:21:49AM -0500, boB Stepp wrote:

> A general question about PEPs:  Is there generally a PEP preceding the
> addition of any new feature to the core language or the standard
> library?  I gather that even an accepted PEP (In this instance PEP
> 0435.) may not reflect the final form of the added feature(s) as I did
> not see direct mention of "auto", though that feature was alluded to.

It depends on the natural of the new feature. Generally only large, 
complex or controversial changes require a PEP. Simple bug fixes or 
small additions to existing functionality don't.

Once a feature/module has been added to the language, the PEP usually 
stops being updated. So it effectively becomes a snapshot of what the 
feature was intended to look like in Version X when it was first added, 
not necessarily what it looks like in Version X+1.


> > Enums have a few other nice properties, which you may or may not care
> > about, but the primary use is to act as set of related named symbols.
> >
> 
> The iterability looks useful.  IntEnum looks interesting.  IntFlag and
> Flag I am currently clueless about.  I would have to dig deeper as I
> don't fully understand their uses yet.

Basically IntEnum and similar exist for compatability with C-style 
enums, which are basically integers. That lets you combine flags with 
bitwise OR. Sometimes that's useful, but its not the default for Python 
enums.


-- 
Steve