bit-count (FURB161)

Derived from the refurb linter.

Fix is always available.

What it does

Checks for uses of bin(...).count("1") to perform a population count.

Why is this bad?

In Python 3.10, a bit_count() method was added to the int class, which is more concise and efficient than converting to a binary representation via bin(...).

Example

x = bin(123).count("1")
y = bin(0b1111011).count("1")

Use instead:

x = (123).bit_count()
y = 0b1111011.bit_count()

Options

• target-version

References

• Python documentation:int.bit_count