# File Management Problem

The academic office at the Hogwarts School of Witchcraft and Wizardry has compiled data about students' grades. The data is provided as text from standard input in three parts: information about courses, information about students and information about grades. Each part has a specific line format, described below.. Information about courses Line format: Course Code~Course Name~Semester~Year~Instructor Information about students Line format: Roll Number~Full Name Information about grades Line format: Course Code~Semester~Year~Roll Number~Grade The possible grades are A, AB, B, BC, C, CD, D with corresponding grade points 10, 9, 8, 7, 6, 5 and 4. The grade point average of a student is the sum of his/her grade points divided by the number of courses. For instance, if a student has taken two courses with grades A and C, the grade point average is 8.50 = (10+7)Γ·2. If a student has not completed any courses, the grade point average is defined to be 0. You may assume that the data is internally consistent. For every grade, there is a corresponding course code and roll number in the input data. Each section of the input starts with a line containing a single keyword. The first section begins with a line containing Courses. The second section begins with a line containing Students. The third section begins with a line containing Grades. The end of the input is marked by a line containing EndOfInput. Write a Python program to read the data as described above and print out a line listing the grade point average for each student in the following format: Roll Number~Full Name~Grade Point Average Your output should be sorted by Roll Number. The grade point average should be rounded off to 2 digits after the decimal point. Use the built-in function round(). Here is a sample input and its corresponding output. Sample Input Courses TRAN~Transfiguration~1~2011-2012~Minerva McGonagall CHAR~Charms~1~2011-2012~Filius Flitwick Students SLY2301~Hannah Abbott SLY2302~Euan Abercrombie SLY2303~Stewart