single char high histogram

histogram

bar_chars = (' ', '▁', '▂', '▃', '▄', '▅', '▆', '▇', '█')

def _draw_histogram(bins):
    mx = max([v for k,v in bins.items()])
    bar_height = (mx / 7)
    if mx == 0:
        return ' ' * len(bins)
    
    histogram = ''
    for k,v in bins.items():
        if v == 0:
            histogram += ' '
        height = int(v / bar_height) + 1
        histogram += bar_chars[height]
        
    return histogram