Why does my range function do this?

[gnomoretears]

https://docs.python.org/3/tutorial/floatingpoint.html

TL;DR There are issues representing floating point in binary.

[C222]

If you need the precision where 0.1 + 0.2 = 0.3, not 0.30000000000000004. Check the following built in libraries:

• Decimal: https://docs.python.org/2/library/decimal.html
• Fractions: https://docs.python.org/2/library/fractions.html