Write a function named baggage_colors that counts the number of bags that can store a "shiny gold" bag in a set of luggage data provided in a file.
Your function accepts a string representing a file name as a parameter where each line of the file data names a unique type of bag, such as a "light red bag", along with what other kinds of bags that bag contains.
Your task is to find the number of lines of the file that end up containing one or more shiny gold bags.
For example, suppose the file named baggage.txt contains the following:
light red bags contain 1 bright white bag, 2 muted yellow bags.
dark orange bags contain 3 bright white bags, 4 muted yellow bags.
bright white bags contain 1 shiny gold bag.
shiny gold bags contain 1 dark olive bag, 2 vibrant plum bags.
dark olive bags contain 3 faded blue bags, 4 dotted black bags.
muted yellow bags contain 2 shiny gold bags, 9 faded blue bags.
vibrant plum bags contain 5 faded blue bags, 6 dotted black bags.
faded blue bags contain no other bags.
dotted black bags contain no other bags.
(1) A light red bag contains 2 muted yellow bags, each of which contains 2 shiny gold bags.
(2) A dark orange bag contains 4 muted yellow bags, each of which contains 2 shiny gold bags.
(3) A bright white bag contains 1 shiny gold bag.
(4) A muted yellow bag contains 2 shiny gold bags.
Four lines eventually lead you to one or more shiny gold bag, so the call of baggage_colors("baggage.txt") should return 4.
You may assume that the file exists and is readable,
that it follows the format described above,
and that there will be at least one line of input in the file.
