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.
Red flag: If your child isn't toddling by 14 or 15 months, bring it up with her doctor. This is still within the normal range of development, but now's a good time to check for anything that may be delaying the milestone. 16 to 18 months. With help, your toddler can walk up and down stairs.