file_size_pretty_print.py

# -*- coding: utf-8 -*-


def pretty_print_file_size(file_size: int, use_base_2: bool = True, approximate: bool = True, suffix: str = 'B'):
    """
    Output a file size as a human friendly str.

    :param file_size: file size in bits to pretty print
    :param use_base_2: choose between base 10 (False) or base 2 (True, default) divider
    :param approximate: drop the float part of the result (True, default)
    :param suffix: file size suffix 'o' for `octets`, 'B' for `Bytes` (default)
    :return: human friendly file size as a str
    """
    # https://en.wikipedia.org/wiki/File_size
    units = ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
    if use_base_2:
        units = ['', 'Ki', 'Mi', 'Gi', 'Ti', 'Pi', 'Ei', 'Zi']

    # loop over known file size prefixes
    for unit in units:
        # if current size is in this range
        if use_base_2 and abs(file_size) < 1024.0\
                or abs(file_size) < 1000.0:
            # return current prefix
            return str(file_size) + unit + suffix
        # divide the file size to get in the next range
        if use_base_2:
            file_size /= 1024.0
        else:
            file_size /= 1000.0

        # drop float part if needed
        if approximate:
            file_size = int(file_size)

    # return the higher prefix we now atm.
    if use_base_2:
        return str(file_size) + 'Yi' + suffix
    return str(file_size) + 'Y' + suffix