Status of PEPs?

John Roth newsgroups at
Wed Jun 30 13:19:29 CEST 2004

"Thomas Reichelt" <XXNOSPAMXX at> wrote in message
news:2kfjf7F1nk33U1 at
> Hello Python-Fans,
> A few months in the past, I learned the Python language and was very
> of it. I have now written many scripts for myself and this opinion stayed,
> not to say, it became more intensive.
> Recently I have discovered the PEP Archive, and my question is now this:
> There are many open ("under consideration") PEPs that would incorporate
> useful features into the language, such as the do-while statement, the
> switch statement or the __main__ function. However, most of these
> are several years old. Though implementations seem to exist for the
> proposals, no action is taken about them. Why is this so? What has to be
> done for a proposal to make it into the language?
> Thank you for answering a dumb question...

It's not a particularly dumb question. The missing piece is that there
are a limited number of core developers, and you need to get a
concensus among them on the Python Dev mailing list that this
particular proposal is more worthy of their time than other
competing proposals. You also need to get it past Guido. Also
note that in two cases you would be adding keywords, which
impose a significant forwards compatibility issue, while the
third has a major issue of non-obviousness.

The proposals you mention all fall into the category of "useful,
but there are other ways of doing that job that work, are well
accepted, and are not a significant burden in terms of either
developer time or comprehensibility."

Put another way, there was a significant against component in the
discussion from the "keep Python simple" crowd.

In other words, to move any of them forward would require submission
of a complete implementation that would work in the current
development tree, together with the necessary documentation
changes, thorough tests, and so on and so forth. That is, someone
who wants to see any of these in Python needs to do the work

A good example of this is the work being done by Facundo Batista
on PEP 327 (Decimal Arithmetic). There's been widespread
agreement for a long time that something should be done about
decimal arithmetic, but until he stepped forward, it sat on dead
center. Now it looks like we're going to get it for Python 2.4,
so it may be possible for us to get a usable currency type in
Python 2.5 (building on the decimal type.)

John Roth

> -- 
> greetz tom

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