111 lines
4.1 KiB
Plaintext
111 lines
4.1 KiB
Plaintext
PEP: 666
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Title: Reject Foolish Indentation
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Version: $Revision$
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Last-Modified: $Date$
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Author: lac@strakt.com (Laura Creighton)
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Status: Rejected
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Type: Standards Track
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Content-Type: text/x-rst
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Created: 03-Dec-2001
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Python-Version: 2.2
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Post-History: 5-Dec-2001
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Abstract
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========
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Everybody agrees that mixing tabs and spaces is a bad idea. Some
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people want more than this. I propose that we let people define
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whatever Python behaviour they want, so it will only run the way
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they like it, and will not run the way they don't like it. We
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will do this with a command line switch. Programs that aren't
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formatted the way the programmer wants things will raise
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``IndentationError``.
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- ``python -TNone`` will refuse to run when there are any tabs.
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- ``python -Tn`` will refuse to run when tabs are not exactly ``n`` spaces
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- ``python -TOnly`` will refuse to run when blocks are indented by anything
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other than tabs
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People who mix tabs and spaces, naturally, will find that their
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programs do not run. Alas, we haven't found a way to give them an
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electric shock as from a cattle prod remotely. (Though if somebody
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finds out a way to do this, I will be pleased to add this option to
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the PEP.)
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Rationale
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=========
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Python-list@python.org (a.k.a. comp.lang.python) is periodically
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awash with discussions about tabs and spaces. This is inevitable,
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given that indentation is syntactically significant in Python.
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This has never solved anything, and just makes various people
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frustrated and angry. Eventually they start saying rude things to
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each other which is sad for all of us. And it is also sad that
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they are wasting their valuable time which they could spend
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creating something with Python. Moreover, for the Python community
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as a whole, from a public relations point of view, this is quite
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unfortunate. The people who aren't posting about tabs and spaces,
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are, (unsurprisingly) invisible, while the people who are posting
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make the rest of us look somewhat foolish.
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The problem is that there is no polite way to say 'Stop wasting
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your valuable time and mine.' People who are already in the middle
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of a flame war are not well disposed to believe that you are acting
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out of compassion for them, and quite rightly insist that their own
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time is their own to do with as they please. They are stuck like
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flies in treacle in this wretched argument, and it is self-evident
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that they cannot disengage or they would have already done so.
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But today I had to spend time cleaning my keyboard because the 'n'
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key is sticking. So, in addition to feeling compassion for these
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people, I am pretty annoyed. I figure if I make this PEP, we can
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then ask Guido to quickly reject it, and then when this argument
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next starts up again, we can say 'Guido isn't changing things to
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suit the tab-haters or the only-tabbers, so this conversation is a
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waste of time.' Then everybody can quietly believe that a) they
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are correct and b) other people are fools and c) they are
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undeniably fortunate to not have to share a lab with idiots, (which
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is something the arguers could do _now_, but apparently have
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forgotten).
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And python-list can go back to worrying if it is too smug, rather
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than whether it is too hostile for newcomers. Possibly somebody
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could get around to explaining to me what is the difference between
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``__getattr__`` and ``__getattribute__`` in non-Classic classes in 2.2, a
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question I have foolishly posted in the middle of the current tab
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thread. I would like to know the answer to that question [2]_.
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This proposal, if accepted, will probably mean a heck of a lot of
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work for somebody. But since I don't want it accepted, I don't
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care.
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References
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==========
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.. [1] PEP 1, PEP Purpose and Guidelines
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http://www.python.org/dev/peps/pep-0001/
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.. [2] Tim Peters already has (private correspondence). My early 2.2
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didn't have a ``__getattribute__``, and ``__getattr__`` was
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implemented like ``__getattribute__`` now is. This has been
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fixed. The important conclusion is that my Decorator Pattern
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is safe and all is right with the world.
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Copyright
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=========
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This document has been placed in the public domain.
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..
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Local Variables:
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mode: indented-text
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indent-tabs-mode: nil
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fill-column: 70
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End:
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