gh-114014: Update `fractions.Fraction()`'s rational parsing regex (#114015)

Fix a bug in the regex used for parsing a string input to the `fractions.Fraction` constructor. That bug led to an inconsistent exception message being given for some inputs.

---------

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
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Crowthebird 2024-01-13 20:02:39 +08:00 committed by GitHub
parent c7d59bd8cf
commit dd56b57483
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3 changed files with 35 additions and 10 deletions

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@ -62,7 +62,7 @@ def _hash_algorithm(numerator, denominator):
(?: # followed by
(?:\s*/\s*(?P<denom>\d+(_\d+)*))? # an optional denominator
| # or
(?:\.(?P<decimal>d*|\d+(_\d+)*))? # an optional fractional part
(?:\.(?P<decimal>\d*|\d+(_\d+)*))? # an optional fractional part
(?:E(?P<exp>[-+]?\d+(_\d+)*))? # and optional exponent
)
\s*\Z # and optional whitespace to finish

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@ -261,6 +261,30 @@ def testFromString(self):
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '1.1e+1__1'",
F, "1.1e+1__1")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '123.dd'",
F, "123.dd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '123.5_dd'",
F, "123.5_dd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: 'dd.5'",
F, "dd.5")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '7_dd'",
F, "7_dd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '1/dd'",
F, "1/dd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '1/123_dd'",
F, "1/123_dd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '789edd'",
F, "789edd")
self.assertRaisesMessage(
ValueError, "Invalid literal for Fraction: '789e2_dd'",
F, "789e2_dd")
# Test catastrophic backtracking.
val = "9"*50 + "_"
self.assertRaisesMessage(

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@ -0,0 +1 @@
Fixed a bug in :class:`fractions.Fraction` where an invalid string using ``d`` in the decimals part creates a different error compared to other invalid letters/characters. Patch by Jeremiah Gabriel Pascual.