def join_number(string, num, width=None):
	"""
	Join a number to the end of a string in the standard way
	If width is provided will backfill
	
	>>> join_number('fred', 10)
	'fred-10'
	>>> join_number('fred', 10, 3)
	'fred-010'
	"""
	num = str(num)
	if width:
		num = num.rjust(width, '0')

	return string + '-' + str(num)