[Tutor] is this a bug?

[Remco Gerlich]

On  0, Michael Goodfellow <mgoodfellow@usa.net> wrote:
> While just working through some list syntax eaxamples, I typed this:
> 
> >>> a = [66.6, 333, 333, 1, 1234.5]
> >>> a # then hit enter key
> 
> # It returned this:
> 
> [66.599999999999994, 333, 333, 1, 1234.5]
> 
> Any comments?

The problem is that, when converted to binary, 66.6 is repeating. There is
no way to represent it exactly in a finite amount of binary digits.

This is not a Python problem but a symptom of the way computers do floating
point math (some other languages may not *show* this, but they have it too).

The str() of a number has an abbreviated form, the repr() shows the Truth.

Compare
>>> str(66.6)
66.6
>>> repr(66.6)
66.599999999999994

-- 
Remco Gerlich