diff options
| author | Wim Jeantine-Glenn <hey@wimglenn.com> | 2024-05-29 17:46:20 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-05-29 17:46:20 (GMT) |
| commit | fcca08ec2f48f4ba5ba1d4690fb39b1efe630944 (patch) | |
| tree | b874582eadea61278f502ed0219e92e5b4fd077e | |
| parent | bf4ff3ad2e362801e87c85fffd9e140b774cef26 (diff) | |
| download | cpython-fcca08ec2f48f4ba5ba1d4690fb39b1efe630944.zip cpython-fcca08ec2f48f4ba5ba1d4690fb39b1efe630944.tar.gz cpython-fcca08ec2f48f4ba5ba1d4690fb39b1efe630944.tar.bz2 | |
gh-119594: Improve pow(fraction.Fraction(), b, modulo) error message (#119593)
If one calls pow(fractions.Fraction, x, module) with modulo not None, the error message now says that the types are incompatible rather than saying pow only takes 2 arguments. Implemented by having fractions.Fraction __pow__ accept optional modulo argument and return NotImplemented if not None. pow() then raises with appropriate message.
---------
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
| -rw-r--r-- | Lib/fractions.py | 4 | ||||
| -rw-r--r-- | Lib/test/test_fractions.py | 6 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2024-05-26-22-22-51.gh-issue-119594.fnQNM8.rst | 1 |
3 files changed, 10 insertions, 1 deletions
diff --git a/Lib/fractions.py b/Lib/fractions.py index f8c6c9c..f91b4f3 100644 --- a/Lib/fractions.py +++ b/Lib/fractions.py @@ -848,7 +848,7 @@ class Fraction(numbers.Rational): __mod__, __rmod__ = _operator_fallbacks(_mod, operator.mod, False) - def __pow__(a, b): + def __pow__(a, b, modulo=None): """a ** b If b is not an integer, the result will be a float or complex @@ -856,6 +856,8 @@ class Fraction(numbers.Rational): result will be rational. """ + if modulo is not None: + return NotImplemented if isinstance(b, numbers.Rational): if b.denominator == 1: power = b.numerator diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py index 3a714c6..3648a89 100644 --- a/Lib/test/test_fractions.py +++ b/Lib/test/test_fractions.py @@ -1633,6 +1633,12 @@ class FractionTest(unittest.TestCase): message % ("divmod()", "complex", "Fraction"), divmod, b, a) + def test_three_argument_pow(self): + message = "unsupported operand type(s) for ** or pow(): '%s', '%s', '%s'" + self.assertRaisesMessage(TypeError, + message % ("Fraction", "int", "int"), + pow, F(3), 4, 5) + if __name__ == '__main__': unittest.main() diff --git a/Misc/NEWS.d/next/Library/2024-05-26-22-22-51.gh-issue-119594.fnQNM8.rst b/Misc/NEWS.d/next/Library/2024-05-26-22-22-51.gh-issue-119594.fnQNM8.rst new file mode 100644 index 0000000..d2de527 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-05-26-22-22-51.gh-issue-119594.fnQNM8.rst @@ -0,0 +1 @@ +If one calls pow(fractions.Fraction, x, module) with modulo not None, the error message now says that the types are incompatible rather than saying pow only takes 2 arguments. Patch by Wim Jeantine-Glenn and Mark Dickinson. |