#  _________________________________________________________________________
#
#  PyUtilib: A Python utility library.
#  Copyright (c) 2008 Sandia Corporation.
#  This software is distributed under the BSD License.
#  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
#  the U.S. Government retains certain rights in this software.
#  _________________________________________________________________________


def format_float(x, precision=None):
    """
    Format float in a portable manner, standardizing the
    number of digits in the exponent.
    """
    if not type(x) is float:
        raise TypeError("Argument " + str(x) + " is not a float")
    tmp = str(x)
    if not ("E" in tmp or "e" in tmp):
        return tmp
    if "+" in tmp:
        sign = "+"
    else:
        sign = "-"
    lst = tmp.split(sign)
    if lst[0] == "" and len(lst) >= 2:
        lst[1] = sign + lst[1]
        lst = lst[1:]
    if abs(x) <= 1e-100 or abs(x) >= 1e100:
        return tmp
    else:
        #
        # Use a 2-digit exponent
        #
        i = 0
        while lst[1][i] == '0':
            i += 1
        return lst[0] + sign + lst[1][i:]


def format_io(x):
    """
    Filter function for controlling the format of objects
    """
    if type(x) is float:
        return format_float(x)
    return str(x)