QUERY · ISSUE

MICROPY_PY_BUILTINS_ROUND_INT==0 breaks round(<int>, <n>)

openby dhalbertopened 2019-05-16updated 2019-08-20

Before https://github.com/micropython/micropython/commit/b318ebf1015ced6354f8bbaf035308214b3f5c5d, which was a rework of #3557, round(<int>, <n>) worked. Now, if MICROPY_PY_BUILTINS_ROUND_INT is set to 0, round(2, 2) or similar throws NotImplementedError. round(2) still works.

@dpgeorge Was it your intention to disable rounding of integers in this way completely, instead of just not handling negative values for the second arg if it was an int?

A user discovered this after ending up with an integer zero while doing some floating arithmetic.

CANDIDATE · PULL REQUEST

py: implemented round(f, N>0), added test

closedby turbinenreiteropened 2015-07-12updated 2015-07-12

In the forum someone asked about round with arguments bigger than 0, and I found that easy enough to be my first patch in C.

(forum thread: http://forum.micropython.org/viewtopic.php?f=2&t=802 )

Assessment

Q Qwen · high

The query (Issue #4792) reports a regression where round(<int>, <n>) fails with NotImplementedError when MICROPY_PY_BUILTINS_ROUND_INT=0, introduced by commit b318ebf which reworked #3557. The candidate (PR #1376) implements round(float, N>0) functionality for floating point numbers, which is a different feature. While both involve the round() builtin and the same code area (py/builtins), PR #1376 addresses floating point rounding with precision, not the integer rounding regression described in the query. The query's issue is about integer rounding being broken, whereas the PR implements floating point rounding that wasn't working before.

Suggested action

Keep both items open. The PR does not resolve the integer rounding regression reported in the issue. The issue should be investigated separately to determine if the regression can be fixed or if the behavior change was intentional.

MICROPY_PY_BUILTINS_ROUND_INT==0 breaks round(<int>, <n>)

py: implemented round(f, N>0), added test

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