[New-bugs-announce] [issue26331] Tokenizer: allow underscores for grouping in numeric literals

[Georg Brandl]

New submission from Georg Brandl:

As discussed on python-ideas: https://mail.python.org/pipermail/python-ideas/2016-February/038354.html

The rules are: 
Underscores are allowed anywhere in numeric literals, except:

* at the beginning of a literal (obviously)
* at the end of a literal
* directly after a dot (since the underscore could start an attribute name)
* directly after a sign in exponents (for consistency with leading signs)
* in the middle of the "0x", "0o" or "0b" base specifiers

Currently this only touches literals, not the inputs of int() or float().  Whether they should accept this syntax is debatable (I'd vote no).

Otherwise missing: doc updates.

Review question: is PyMem_RawStrdup/RawFree the right API to use here?

----------
components: Interpreter Core
files: numeric_underscores.diff
keywords: patch
messages: 260026
nosy: georg.brandl
priority: normal
severity: normal
stage: patch review
status: open
title: Tokenizer: allow underscores for grouping in numeric literals
type: enhancement
versions: Python 3.6
Added file: http://bugs.python.org/file41888/numeric_underscores.diff

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