'''
    DS2000
    Spring 2022
    
    Sample code from class - practice with dictionaries!
    
    Input file has geographical data for NEU students, and has the form:
        state, amount
        state, amount
        state, amount
    
    
    we want to transform the input file into a dictionary where key = 
    state, and value = num students from that state
'''

import csv

NEU_FILE = "neu_geo.csv"

def csv_to_dict(filename):
    ''' Function: csv_to_dict
        Parameter: filename, a string
        Returns: a dictinoary where key - state (str),
                 value - num students (int)
    '''
    data = {}
    with open(filename, "r") as infile:
        csvfile = csv.reader(infile, delimiter = ",")
        next(csvfile)
        for row in csvfile:
            data[row[0]] = int(row[1])
    return data

def max_state(count_dct):
    ''' Function: max_state
        parameter: dictionary where  key - string,
                    value - num of occurrences
        returns: a tuple (key, value) for the highest value in
                the dictionary
    '''
    max_key = ""
    max_value = -1
    for key, value in count_dct.items():
        if value > max_value:
            max_value = value
            max_key = key
    return (max_key, max_value)
    

def main():
    # Step one: gather data from the csv file
    states = csv_to_dict(NEU_FILE)
    
    # step two - computation,
    # find the state with the most students
    state, students = max_state(states)
    
    # step three - communciation
    print(state, "has the most students at NEU, with", 
          students)
    
    # # Step two: computation
    # state = input("Which state to find out?\n")
    # num_students = states[state]
    
    # # Step three: communicate! print out
    # print("There are", num_students, "students from", state)
main()