def _sortValue_isMonospace(font):
    if font.info.postscriptIsFixedPitch:
        return 0
    if not len(font):
        return 1
    testWidth = None
    for glyph in font:
        if testWidth is None:
            testWidth = glyph.width
        else:
            if testWidth != glyph.width:
                return 1
    return 0