human
What is a the Python program you requested given the following:
Complete the below
def _describe_style(which_styles):

    ''''Returns a string describing a linear combination of styles.'
    '''
assistant
#Here is the Python program you requested.
    def _format(v):
        formatted = str(int(round((v * 1000.0))))
        while (len(formatted) < 3):
            formatted = ('0' + formatted)
        return formatted
    values = []
    for k in sorted(which_styles.keys()):
        values.append(('%s_%s' % (k, _format(which_styles[k]))))
    return '_'.join(values)