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redundant-log-base (FURB163)

Added in 0.5.0 · Related issues · View source

Derived from the refurb linter.

Fix is sometimes available.

What it does

Checks for math.log calls with a redundant base.

Why is this bad?

The default base of math.log is e, so specifying it explicitly is redundant.

Instead of passing 2 or 10 as the base, use math.log2 or math.log10 respectively, as these dedicated variants are typically more accurate than math.log.

Example

import math

math.log(4, math.e)
math.log(4, 2)
math.log(4, 10)

Use instead:

import math

math.log(4)
math.log2(4)
math.log10(4)

Fix safety

This fix is marked unsafe when the argument is a starred expression, as this changes the call semantics and may raise runtime errors. It is also unsafe if comments are present within the call, as they will be removed. Additionally, math.log(x, base) and math.log2(x) / math.log10(x) may differ due to floating-point rounding, so the fix is also unsafe when making this transformation.

References