carlsmith

def render(digits):
    
    '''This function converts its input, a string of decimal digits, into a
    barcode, using the interleaved 2 of 5 format. The input string must not
    contain an odd number of digits. The output is an SVG string.

    Wikipedia [ITF Format]: http://en.wikipedia.org/wiki/Interleaved_2_of_5
    '''

    top = '<svg height="58" width="{0}" style="background:white">'