Write a python code in class with objects to handle the following functionalities:

a$.$ Read in the names of the students, their grade for each of the course $($ET$2160,$ ET$2140,$ EET$2100$ and EET$3300)$

b$.$ Calculate the averaged score for each student

c$.$ Calculate the letter grade based on the averaged score, $($if the averaged score is between $90-100,$ that's A; $80-89$: B$,70-79$: C$,60-69$: D$,$ below $60$ means F$)$

d$.$ Print out all students information, column $1-$names, column$2-$ET$2140,$ column$3-$ET$2160,$ column$4-$EET$2100,$ column$5-$EET$3300,$ column$6-$Averaged score for each student; column$7-$ Letter Grade $($A$,$ B$,$ C$,$ D$,$ F$)$

e$.$ Calculate the number of students based on letter grade $($A$,$ B$,$ C$,$ D$,$ F$),$ such as $5$ students received $A,7$ students received $B,2$ students received $C,1$ student received D and $1$ students failed.

f$.$ Include all key information into a data frame.