import math


def myceil(x, base=10):
    """
    Returns the upper-bound integer of 'x' in base 'base'.

    Parameters
    ----------
    x: float
        number to be approximated to closest number to 'base'

    base: float
        base used to calculate the closest 'largest' number

    Returns
    -------
    n_high: float
        Closest float number to 'x', i.e. upper-bound float.

    Example
    -------
    >>>> myceil(12,10)
      20
    >>>>
    >>>> myceil(12.05, 0.1)
     12.10000 
    """
    n_high = float(base*math.ceil(float(x)/base))

    return n_high