frange(), a range function with float increments (Python recipe) by Dinu Gherman ActiveState Code (http://code.activestate.com/recipes/66472/) Sadly missing in the Python standard library, this function allows to use ranges, just as the built-in function range(), but with float arguments. All thoretic restrictions apply, but in practice this is more useful than in theory.
When I worked at a daycare we would have bike day during the summer when kids, aged 3-5, could bring in their bikes and ride them, most of the kids were on big bikes with training wheels and a few of the 4-5 year olds were without training wheels.
Child development experts believe that motor activity during the second year is vital to the child's competent development and that few restrictions, except for safety, should be placed on their motoric adventures. By 13 to 18 months, toddlers can move up and down steps and carry toys.