I need the code in python or a psudecode

thanks

Problem 2. (20 points) In this problem the input file will have classes listed with their prerequisites. Your output.txt should list a valid order for taking all of these classes while meeting all the prerequisites. You may assume there are no circular prerequisites (i.e. class A requires class B. Class B requires class C. Class C requires class A). You may assume all classes that are prerequisites of another are listed The courses can be any string (not necessarily numbers) Sample input file (course identifier before ":". Prerequisites after" with spaces between): 1001: 1133: 2011: 1933:1133 4041:1933 2011 Sample output.txt (valid class ordering with spaces between (no space after final class)): 1133 2011 1933 4041 1001