[New-bugs-announce] [issue15245] ast.literal_eval on some literals

[João Bernardo]

New submission from João Bernardo <jbvsmo at gmail.com>:

`ast.literal_eval` is very strict on names, so it seems to lack some "literals" that may be result of `repr` on built-in objects.

-> Obvious cases:

ast.literal_eval('...')
ast.literal_eval('Ellipsis')

both result on ValueError.



-> Not so obvious:

nan_name = repr(float('nan'))
ast.literal_eval(nan_name) # ValueError

inf_name = repr(float('inf'))
ast.literal_eval(inf_name)  # ValueError

ast.literal_eval("2e308") # == inf


`nan` and `inf` are not literals (at least "inf" should be, but that's another problem), but their representations are not possible to be evaluated unlike any other float numbers with maybe precision loss. 

I think `literal_eval` should include these 3 names the same way it accepts True, False and None.

Another case, that I personally don't care, but seems plausible would be `NotImplemented`.

----------
components: Library (Lib)
messages: 164621
nosy: JBernardo
priority: normal
severity: normal
status: open
title: ast.literal_eval on some literals
type: enhancement
versions: Python 3.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue15245>
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