from statistics import mean as m

SDict = {'Jeff':[78,88,93],
         'Alex':[92,76,88],
         'Sam': [89,92,93]}

admins = {'Jenny':'8675309',
          'Jimmy':'Hendrix'}

def home():

    print('''\n Welcome to Inner City Schools!
    [1] - Enter grades.
    [2] - Remove a student.
    [3] - Student average grades.
    [4] - Exit
    ''')


    action = input('\n''What would you like to do?: ')

    if action == '1':
        print('You have chosen to enter grades''\n')
        addGrade()

    elif action == '2':
        print('You have chosen to remove a student.''\n')
        removeStudent()

    elif action == '3':
        StAvg()

    elif action == '4':
        print('Goodbye.')
        exit()

    else:
        print('Please try again.')


def addGrade():
    student = input('Please enter student name: ')
    grade = input('Please enter '+student+'\'s grade: ')

    if student in SDict:
        print('Adding grade...')
        SDict[student].append(float(grade))
    else:
        print('No student by that name.')

    print(SDict)


def removeStudent():
    student = input('Please enter student name: ')

    if student in SDict:
        print('Removing student...')
        del SDict[student]
    else:
        print('\n''No student by that name.''\n')

    print(SDict)

def StAvg():
    for eachStudent in SDict:
        gradeList = SDict[eachStudent]
        avgGrade = m(gradeList)

        print(eachStudent,'Has an average grade of:', avgGrade)


login = input('username: ')
passw = input('Password: ')

if login in admins and admins [login] == passw:
    print('Welcome',login)
    while True:
        home()
else:
    print('Invalid username or password')