QUERY · ISSUE

docs: non standard behaviour of float()

openby massimosalaopened 2023-06-22updated 2025-11-06

docs

See
https://github.com/micropython/micropython/issues/11735

The official page
https://docs.micropython.org/en/latest/genrst/builtin_types.html#float
should be updated about the different result of

float('_')

(and eventually other invalid inputs)
between Python and MicroPython.

CANDIDATE · ISSUE

docs: Document limited numerical precision

openby tdunningopened 2024-06-11updated 2025-03-03

docs

Documentation URL

No response

Description

Python normally uses double precision for all (floating point operations)[https://docs.python.org/3/library/numbers.html#numbers.Real]. MicroPython, depending on the platform, usually does not. This leads to surprises and errors, occasionally quite serious.

Unfortunately, this doesn't seem to be documented anywhere except in discussion groups.

I will create a pull request which attempts to deal with this lack.

Code of Conduct

Yes, I agree

Assessment

Q Qwen · high

Both issues are documentation requests related to MicroPython's float behavior, but they address different specific problems. Issue #11843 focuses on documenting the non-standard behavior of float() when parsing invalid string inputs (like '_') compared to CPython. Issue #15258 focuses on documenting platform-dependent floating-point precision limitations. While both concern float() documentation and Python compatibility, they cover distinct aspects of float behavior and would require different documentation updates.

Suggested action

Keep both issues open as they address separate documentation needs. The maintainer may consider linking them if they decide to create a comprehensive float() documentation page that covers both parsing behavior and precision limitations.