closest.py

def closest(val, vallist, index=True):
    """ returns the closest value or index to a date in a list

    ===========         ======================
    keyword             description
    -----------         ----------------------
    index               [True] returns index
    ===========         ======================

    """
    #assert isinstance(date,dt.datetime), "date must be a datetime object"
    minval = sorted(vallist, key=lambda d: abs(val - d))[0]
    if index is not True:
        return minval
    else:
        if not isinstance(vallist, list):
            vallist = list(vallist)
        return vallist.index(minval)