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| author | Arthur Milchior <arthur@milchior.fr> | 2022-04-02 22:11:20 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-04-02 22:11:20 (GMT) |
| commit | ebbdbbff5d6840807e46ec61b8a323e94ee88de2 (patch) | |
| tree | 19390e3ce150e385d1fad9e7a13ebfa871457667 | |
| parent | 1f80dcd2442f2a354097797fedc077592984903b (diff) | |
| download | cpython-ebbdbbff5d6840807e46ec61b8a323e94ee88de2.zip cpython-ebbdbbff5d6840807e46ec61b8a323e94ee88de2.tar.gz cpython-ebbdbbff5d6840807e46ec61b8a323e94ee88de2.tar.bz2 | |
bpo-45584: Clarify `math.trunc` documentation (GH-29183)
While floor/ceil 's documentation are very precise, `truncate` was not explained. I actually had to search online to understand the difference between `truncate` and `floor` (admittedly, once I remembered that numbers are signed, and that floating numbers actually uses a bit for negation symbol instead of two complement, it became obvious)
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Éric Araujo <merwok@netwok.org>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
| -rw-r--r-- | Doc/library/math.rst | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/Doc/library/math.rst b/Doc/library/math.rst index c0f9614..48030fa 100644 --- a/Doc/library/math.rst +++ b/Doc/library/math.rst @@ -32,8 +32,8 @@ Number-theoretic and representation functions .. function:: ceil(x) Return the ceiling of *x*, the smallest integer greater than or equal to *x*. - If *x* is not a float, delegates to ``x.__ceil__()``, which should return an - :class:`~numbers.Integral` value. + If *x* is not a float, delegates to :meth:`x.__ceil__ <object.__ceil__>`, + which should return an :class:`~numbers.Integral` value. .. function:: comb(n, k) @@ -77,9 +77,9 @@ Number-theoretic and representation functions .. function:: floor(x) - Return the floor of *x*, the largest integer less than or equal to *x*. - If *x* is not a float, delegates to ``x.__floor__()``, which should return an - :class:`~numbers.Integral` value. + Return the floor of *x*, the largest integer less than or equal to *x*. If + *x* is not a float, delegates to :meth:`x.__floor__ <object.__floor__>`, which + should return an :class:`~numbers.Integral` value. .. function:: fmod(x, y) @@ -298,9 +298,11 @@ Number-theoretic and representation functions .. function:: trunc(x) - Return the :class:`~numbers.Real` value *x* truncated to an - :class:`~numbers.Integral` (usually an integer). Delegates to - :meth:`x.__trunc__() <object.__trunc__>`. + Return *x* with the fractional part + removed, leaving the integer part. This rounds toward 0: ``trunc()`` is + equivalent to :func:`floor` for positive *x*, and equivalent to :func:`ceil` + for negative *x*. If *x* is not a float, delegates to :meth:`x.__trunc__ + <object.__trunc__>`, which should return an :class:`~numbers.Integral` value. .. function:: ulp(x) |