Create the following functions: calculateaverage(studentname): returns the average of a student's grades according to the name supplied. lowestgrade(studentname): returns the lowest grade for a student according to the name supplied. highestgrade(studentname): returns the highest grade for a student according to the name supplied. then, in a main() function, write code that accepts a name from the user, and displays the following text, with the corresponding data:

#a global variable that would store the grades of all students

#it would be a dictionary of lists. One can opt for any other data type

grades={"bob":[3,4,2.5], "alice": [2.3,3.1,2]}

#this is the function that calculates average

def calculateAverage(studentName):

#the for loop is for iteration. we iterate over dictionary items

    for student, grade in grades.items():

#we check if student record exists

          if student==studentName:

           average= sum(grade)/len(grade)

           return(average)

       else:

           print("student does not exist  :")

#the calculate Average function ends here

#this is the function that calculates lowest grade

def lowestGrade(studentName):

   for student, grade in grades.items():

       if student==studentName:

           return(min(grade))

       else:

           print("student does not exist  :")

#the lowestgrade function ends here

#this is the function that calculates highest grade

def highestGrade(studentName):

   for student, grade in grades.items():

       if student==studentName:

           return(max(grade))

       else:

           print("student does not exist  :")

#the highest grade function ends here

#main function

def main():

   studentname=input("please input student name: ")

   print("the average gpa of {}: is {}".format(studentname,calculateAverage(studentname)))

   print("the lowest grade of {}: is {}".format(studentname,lowestGrade(studentname)))

   print("the heighest gpa of {}: is {}".format(studentname,highestGrade(studentname)))

#main function ends

main()

Explanation: