def rule_passes(rule_regexp, product_repr):
	""" 
		rule: rule(keep, drop)_A_B_C_D
		product: A_B_C
	"""	
	#we have altered the rules to have "*" as the 4th parameter (if split by _) 
	# so all the D's will pass
	return rule_regexp.match(product_repr+"_")