Bugs item #1153226, was opened at 2005-02-27 23:10 Message generated for change (Comment added) made by montanaro You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1153226&group_id=5470
Category: Python Interpreter Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stephen Thorne (jerub) Assigned to: Nobody/Anonymous (nobody) Summary: string interpolation breaks with %d and large float Initial Comment: We have experienced a problem recently when wanting to render a large float as a string. Converting the float to an int/long manuall was required. '%d' % f throws an exception for all floats f, f >= 2**31 Expected output, shown with 'int()' and 'long()': >>> '%d %d' % (long(float(2**31)), int(float(2**31))) '2147483648 2147483648' Non-Working Example. >>> '%d' % float(2**31) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: int argument required Tested on: Python 2.3.4 (#1, Oct 26 2004, 16:42:40) Python 2.4.1a0 (#2, Feb 9 2005, 22:42:24) ---------------------------------------------------------------------- >Comment By: Skip Montanaro (montanaro) Date: 2005-03-01 18:42 Message: Logged In: YES user_id=44345 Sorry, I got corn-fused and misinterpreted 2**50 as 2e50. ---------------------------------------------------------------------- Comment By: Stephen Thorne (jerub) Date: 2005-03-01 17:53 Message: Logged In: YES user_id=100823 %ld doesn't help. see the following example: >>> "%.f" % float(2**31) '2147483648' >>> "%ld" % float(2**31) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: int argument required ---------------------------------------------------------------------- Comment By: Skip Montanaro (montanaro) Date: 2005-03-01 09:38 Message: Logged In: YES user_id=44345 This is probably a corner case that got missed in the int/long convergence. Still, is there a reason not to use %.f when you know you are passing a float and want to display it with no fractional component? >>> '%.f' % 2**50 '1125899906842624' or %ld if you expect the range to exceed the integer limits of your hardware? >>> '%ld' % 2**50 '1125899906842624' I agree the documentation could probably be improved in this area. ---------------------------------------------------------------------- Comment By: Stephen Thorne (jerub) Date: 2005-03-01 07:21 Message: Logged In: YES user_id=100823 My immediate reaction is, yes. This is a bug. Either floats should work with %d, or they should not at all. Having a platform dependant upper bound on the size of the float allowed is a bug. ---------------------------------------------------------------------- Comment By: Josiah Carlson (josiahcarlson) Date: 2005-03-01 00:36 Message: Logged In: YES user_id=341410 Note that it will also raise a TypeError when the float f, f < -2**31 Is this a bug? I don't know. I tend to not pass floats when string interpolation is expecting integers. Maybe the documentation should be cleared up. If you really want a truncated float, perhaps "%.0f" is the format you are looking for, to save you the effort of using int() or long(). ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1153226&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
