'''
Author: Sohie Lee
Purpose: Lab 09 Dictionaries 
Date: Spring 22
Purpose: practice inverting the keys and values of a given dictionary
Filename: invert.py 
'''

# ---------------------------
# Provided code; do not edit 
# ---------------------------
from nameYear import *

def makeCS111Dict(students):
    '''Returns a name:year dictionary built from the
    nameYear.py file
    '''
    newdict = {}

    for person in students:  # person looks like this: ['Kathryn', '2021']
        name = person[0]
        year = person[1]
        newdict[name] = year
        
    return newdict
    
# ------------------------------------------------------------
# Write your invertDict function here
# ------------------------------------------------------------
def invertDict(origDict):
    '''Given origDict, return an inverted dictionary such that
    the keys become the values and the values become the keys.
    '''
    inverted = {}
    for student in origDict:
        year = origDict[student]
        if year in inverted: # year already exists as key in new dict
            inverted[year].append(student)
        else: # create new key:value pair
            inverted[year] = [student] # make sure it is a list
    return inverted


#--------------#
# Testing code #
#--------------#
cs111dict = makeCS111Dict(nameYear)
print(len(cs111dict))
    
print("Invert the 111 dict")
inverted = invertDict(cs111dict)
print(inverted.keys())
print("**2021**\n",inverted['2021'])
print("**2022**\n",inverted['2022'])
print("**2023**\n",inverted['2023'])
print("**2024**\n",inverted['2024'])