Quick and dirty function to build a google pie chart url

pychart.py

def piechart(data, labels=None, colors=None, size='600x400'):
    '''Accepts a list to graph.  Optionally accepts labels and colors.  Both optional arguments
    must have the same len as the data.'''
    baseurl = 'https://chart.googleapis.com/chart?cht=p'
    chs = 'chs={}'.format(size)
    chd = 'chd=t:{}'.format(','.join([str(i) for i in data]))
    chds = 'chds=0,{}'.format(sum(data))
    if labels:
        chl = 'chl={}'.format('|'.join(
            ['{}: {}'.format(y, data[x]) for x,y in enumerate(labels)]))
    else:
        chl = None
    if colors:
        if type(colors) == str:
            chco = 'chco={}'.format(colors)
        elif len(colors) == 2:
            chco = 'chco={}'.format(','.join(colors))
        else:
            chco = 'chco={}'.format('|'.join(colors))
    else:
        chco = 'chco={}'.format('|'.join(
            hex(random.randint(0, 16777215))[2:].upper().zfill(6) for i in range(len(data))))
    output = []
    for i in baseurl, chs, chd, chds, chl, chco:
        if i:
            output.append(i)
    return '&'.join(output)