human
I wrote the below code

    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)

What's a good function header?

=====
Here's a good function header?
assistant
#Here's a good function header.

def _describe_style(which_styles):