[Python-bugs-list] [ python-Bugs-481726 ] literal fp pound errors pass silently
noreply@sourceforge.net
noreply@sourceforge.net
Wed, 14 Nov 2001 10:07:22 -0800
Bugs item #481726, was opened at 2001-11-14 08:00
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http://sourceforge.net/tracker/?func=detail&atid=105470&aid=481726&group_id=5470
Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Grant Griffin (dspguru)
Assigned to: Nobody/Anonymous (nobody)
Summary: literal fp pound errors pass silently
Initial Comment:
It looks like anything beyond a pound sign in a
floating point literal is allowed, but ignored. Here
are a couple of examples:
----------
Python 2.2b1 (#25, Oct 19 2001, 11:44:52) [MSC 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for
more information.
>>> a=1.#INF
>>> a
1.0
ActivePython 2.1.1, build 212 (ActiveState)
Python 2.1.1 (#20, Jul 26 2001, 11:38:51) [MSC 32 bit
(Intel)] on win32
Type "copyright", "credits" or "license" for more
information.
>>> a=1.#asdf
>>> a
1.0
>>> a=2.#INF
>>> a
2.0
-----------
It seems like this notation should either be
disallowed totally, or at least be disallowed when it
does not result in a valid IEEE magic number (as in
the second and third examples).
Also, maybe this has an impact on pickling if IEEE
magic numbers cannot be remade from their strings, e.g.
>>> x=1e300
>>> y=x*x
>>> y
1.#INF
>>> z=float(str(y))
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: invalid literal for float(): 1.#INF
(Note that "float()" does not accept the "#" notation,
but the parser does.)
thanks,
=g2
----------------------------------------------------------------------
>Comment By: Michael Hudson (mwh)
Date: 2001-11-14 10:07
Message:
Logged In: YES
user_id=6656
You haven't forgotten the fact that # is the comment
character in Python, have you?
This makes it "tricky" to implement reading
1.#INF
as anything other than
1.
!
----------------------------------------------------------------------
You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=481726&group_id=5470