[ python-Bugs-1732212 ] repr of 'nan' floats not parseable

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Bugs item #1732212, was opened at 2007-06-06 16:50
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Category: Python Interpreter Core
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Pete Shinners (shredwheat)
Assigned to: Nobody/Anonymous (nobody)
Summary: repr of 'nan' floats not parseable

Initial Comment:
The repr of float('nan') is not parsable as a literal in Python.

If the repr of 'nan' became "float('nan')" then the result could be evaluated to produce the same results.

A better possible solution would be to add "nan" and "inf" as attributes on float. These would be accessed as "float.nan" and "float.inf". This doesn't allow for "-inf" as cleanly, but "float.ninf" could be acceptable. Repr would be changed to return these.

A patch can be provided if the solution sounds resonable.



>>> repr((1.0, 2.0, 3.0))
'(1.0, 2.0, 3.0)'
>>> eval(_)
(1.0, 2.0, 3.0)

>>> repr((1.0, float('nan'), 3.0))
'(1.0, nan, 3.0)'
>>> eval(_)
NameError: name 'nan' is not defined


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