Wikipedia [1] doesn't list any country that does use the colon (:) as the decimal separator, so possibly the period/dot (.) as used in most English-speaking countries, was meant?
Yeah, I think what author meant "some countries don't use the period but a comma, thus hilarity ensues" (especially when your code respects the locale and the csv file is written in append mode)
Wikipedia [1] doesn't list any country that does use the colon (:) as the decimal separator, so possibly the period/dot (.) as used in most English-speaking countries, was meant?
1: https://en.wikipedia.org/wiki/Decimal_separator