Bugs item #925537, was opened at 2004-03-29 14:28 Message generated for change (Settings changed) made by jimjjewett You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=925537&group_id=5470

Category: Python Library Group: Python 2.4 Status: Open Resolution: None

Submitted By: Jim Jewett (jimjjewett) Assigned to: Nobody/Anonymous (nobody) Summary: dir(mod) OK or use vars(mod).keys()?

Initial Comment: The documentation on dir() notes that its behavior may change across releases.

Several library modules use dir(x) in ways that might break if it changed too much.

Should these be changed to use vars(obj).keys() (and possibly sort()), or should the note on dir() be removed?

My own preference would just be to provide some guidance, such as "The output of dir() will always include all public variables which do not have a magic meaning."

I realize that the standard library itself could be updated if dir() changes in an uncomfortable way. My real concern is which spelling to use in my own code. The library examples suggest a simpler (and clearer) dir(), but the documentation still says otherwise.

A quick search for modules using dir() showed possible trouble in at least cgitb, cmd, FCNTL, inspect, optparse, os, pickle, rlcompleter, SimpleXMLRPCServer, TERMIOS, tokenize, unittest, and urllib2.

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Comment By: Jim Jewett (jimjjewett) Date: 2004-03-29 14:58

Message: Logged In: YES user_id=764593

Correction: "The output of dir (module) will always include ..."

The most common use is figuring out what to do with (import from) a module.

Symmetry suggests the same for a no-argument call or a class or type object, but object instances do not use their __dict__ for their attributes; the results are already different there.

-jJ

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Comment By: Jim Jewett (jimjjewett) Date: 2004-03-29 14:39

Message: Logged In: YES user_id=764593

If there concern is over attributes that are "public" but don't exist until called, then most uses of dir and vars are already broken. An alternative reasonable promise would be

The output of dir(obj) will always include all (public?, non-magical?) names in vars(obj).keys().

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