def roundGrade(grades):
    gradesRounded = []
    for grade in grades:
        grade = round(grade)
        if grade < -1.5:
            grade = -3
        elif grade < 1:
            grade = 0
        elif grade < 3:
            grade = 2
        elif grade < 5.5:
            grade = 4
        elif grade < 8.5:
            grade = 7
        elif grade < 11:
            grade = 10
        else:
            grade = 12
        gradesRounded.append(grade)
    return gradesRounded

def computeFinalGrades(grades):
    moreThanOneAssignment = True
    gradesFinal = []
    for student in grades:
        if -3 in student:
            gradesFinal.append(-3)
        elif len(student) > 1:
            studentSum = 0
            for individualGrade in sorted(student)[1:]:
                studentSum += int(individualGrade)
            studentSum = float(studentSum) / float(len(student)-1)
            gradesFinal.append(studentSum)
        else:
            gradesFinal.append(student[0])
    return gradesFinal

vector = [[3,4,5],
         [2,3,4],
         [9,11,8],
         [-3,4,6]]

def gradesPlot(grades):
    # Final grades
    plt.hist(roundGrade(computeFinalGrades(grades)))
    plt.show()

def loadCSV(file):
    file = list(csv.reader(open(file)))
    return file
def checkDataErrors(data):
    error = False
    #Multiple students
    studentList = []
    for student in data:
        studentList.append(student[0])
    for student in studentList:
        count = studentList.count(student)
        if count > 1:
            print ("There are " + str(count) + " students with the ID: " + str(student))
            error = True
    if error == False:
        print ("There are no known errors in the data.")

def fileToVector(data):
    gradeVector = []
    for student in data[1:]:
        results = list(map(int, student[2:]))
        gradeVector.append(results)
    return gradeVector

def displayListOfGrades(data):

    # Display grades for assignment
    assignments = len(data[0])-2
    for i in range(assignments):
        gradeList = []
        for student in data[1:]:
            gradeList.append(student[i+2])
        print ("Assignment " + str(i) + ": " + str(gradeList))
    print ("")

    finalGrades = roundGrade(computeFinalGrades(fileToVector(data)))

    print ("")

    studentList = []
    for student in data[1:]:
        studentList.append(student[1])

    studentDict = {}
    for i in range(len(studentList)):
        studentDict[studentList[i]] = finalGrades[i]

    for name in sorted(studentDict.keys()):
        print (name + ": " + str(studentDict[name]))

print ("Welcome to my program!")
dataLoaded = False
shouldRun = True
file = loadCSV("exam2.csv")
while shouldRun:

    print ("***Options***")
    print ("1: Load data")
    print ("2: Check for data errors")
    print ("3: Generate plots")
    print ("4: Display list of grades")
    print ("0: Quit")

    var = input("Command: ")
    isANumber = False
    try:
        var = int(var)
        isANumber = True
    except:
        print ("Input not a number.")
        isANumber = False

    if isANumber:
        if int(var) == 0:
            print ("You quit the script")
            break
        elif int(var) == 1:
            fileName = input("CSV file name (remember .csv): ")
            file = loadCSV(fileName)
            print (file)
        elif int(var) == 2:
            checkDataErrors(file)
        elif int(var) == 3:
            gradesPlot(fileToVector(file))
        elif int(var) == 4:
            displayListOfGrades(file)
        else:
            print ("Input not valid.")

    print ("")