[issue7028] Add int.hex for symmetry with float.hex

[Mark Dickinson]

Mark Dickinson <dickinsm at gmail.com> added the comment:

> Can int.hex() and int.fromhex() be added for symmetry?

On the face of it, adding int.hex (and presumably also long.hex for 2.x)
seems reasonable:  in general, integers should be acceptable where-ever
floats are, and by that argument x.hex() should work regardless of
whether x is an integer or a float.

However, I'm opposed to adding int.hex, for a few reasons:

  - the problem that float.hex solves is special to floats, namely that
    the usual representation of a float (via repr) doesn't show the
    *exact* value of that float clearly.  This isn't a problem for
    integers, Fractions, Decimals, etc.

  - there's no danger of silent errors here:  x.hex() will raise an
    exception if x is an integer, giving the programmer an opportunity
    to correct this to e.g.  'float(x).hex()', or perhaps
    'x.hex() if isinstance(x, float) else hex(x)'.  But which one?
    Which leads me to:

  - it's not clear what the output of n.hex() would be:  e.g., should
    (3).hex() match (3.0).hex(), or hex(3)?  Or should it be something
    else again? I'd suggest that different use-cases would need
    different choices here.

  - TSBO---APOO---OWTDI  (see 'import this')

  - I just don't see a real usecase for int.hex.  float.hex is a
    little-used but nice-to-have convenience function.  When it's
    used, it's almost certainly being used on a float.  Feel free
    to give examples of code that would benefit from int.hex.

The case for adding int.fromhex is even weaker: float.fromhex is a class
method, and will usually be called in the form
'float.fromhex(mystring)'.  If you already know you want a hex_string to
int conversion, what's wrong with int(my_string, 16)?

In short, PBP (see 'import this' again).

If you really care about this, you could take the discussion to the
python-ideas mailing list and try to persuade people there; if everyone
feels that int.hex() *should* be added then I'll happily eat my words
and agree to add it.

Raymond, care to offer a second opinion?

----------
components: +Interpreter Core -Library (Lib)
nosy: +rhettinger
resolution: out of date -> 
status: closed -> open
title: hex function should work with floats -> Add int.hex for symmetry with float.hex
versions: +Python 2.7, Python 3.2 -Python 3.1

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue7028>
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