Django quantity format template tag/filter

django_template_filters.py

@register.filter(name='quantityformat')
def quantityformat(bytes):
    """
    Formats the value like a 'human-readable' file size (i.e. 13K, 4.1M,
    102, etc).
    """
    try:
        bytes = float(bytes)
    except (TypeError,ValueError,UnicodeDecodeError):
        return ungettext("%(size)d", "%(size)d", 0) % {'size': 0}

    filesize_number_format = lambda value: formats.number_format(round(value, 1), 1)

    if bytes < 1024:
        return ungettext("%(size)d", "%(size)d", bytes) % {'size': bytes}
    if bytes < 1024 * 1024:
        return ugettext("%sK") % filesize_number_format(bytes / 1024)
    if bytes < 1024 * 1024 * 1024:
        return ugettext("%sM") % filesize_number_format(bytes / (1024 * 1024))
    if bytes < 1024 * 1024 * 1024 * 1024:
        return ugettext("%sG") % filesize_number_format(bytes / (1024 * 1024 * 1024))
    if bytes < 1024 * 1024 * 1024 * 1024 * 1024:
        return ugettext("%sT") % filesize_number_format(bytes / (1024 * 1024 * 1024 * 1024))
    return ugettext("%sP") % filesize_number_format(bytes / (1024 * 1024 * 1024 * 1024 * 1024))
quantityformat.is_safe = True