Taking the floor of a float

Question

I have found two ways of taking floors in Python:

3.1415 // 1

and

import math
math.floor(3.1415)

The problem

Answer 1

from math import floor


def ff(num, step=0):
    if not step:
        return floor(num)
    if step < 0:
        mplr = 10 ** (step * -1)
        return floor(num / mplr) * mplr
    ncnt = step
    if 1 > step > 0:
        ndec, ncnt = .0101, 1
        while ndec > step:
            ndec *= .1
            ncnt += 1
    mplr = 10 ** ncnt
    return round(floor(num * mplr) / mplr, ncnt)

You can use positive/negative numbers and float points .1, .01, .001...