I can run it and get the correct ans...

# The dictionary will look something like:
# {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Each key will be a Teacher and the value will be a list of courses.
#
# Your code goes below here.

def num_teachers(argument):
    teacher_list = []
    for teacher in argument:
        teacher_list.append(teacher)
    return len(teacher_list)

def num_courses(argument):
    course_list = []
    for course in argument.values():
        course_list += course
    return len(course_list)

def courses(argument):
    course_list2 = []
    for course in argument.values():
        course_list2 += course
    return course_list2

def most_courses(argument):
    max_course = 0
    for teacher in argument.keys():
        if len(argument[teacher]) > max_course:
            max_course = len(argument[teacher])
    return teacher