def main():
    from random import randint
    print('==Exercise 4==')
    LIST_A = [1,2.0,'c',{"id":4}]
    LIST_B = [randint(1,20) for i in range(10)]
    LIST_C = [*[chr(i+65) for i in range(10)],27,28.0]
    
    print('Lists Initial Values:')

    """
    updated on Mar 23th 23:00
    课上写的有点问题，重写了
    print(f'{i["idtf"]}: {i["value"]}' for i in [
        {"idtf":"List A","value":LIST_A},
        {"idtf":"List B","value":LIST_B},
        {"idtf":"List C","value":LIST_C},
        ])
    """

    print(*[f'{i["idtf"]}: {i["value"]}' for i in [
        {"idtf":"List A","value":LIST_A},
        {"idtf":"List B","value":LIST_B},
        {"idtf":"List C","value":LIST_C},
        ]],sep='\n')
    
    print('a range of items: ',LIST_C[:-3])
    print('reverse print of list: ',LIST_C[::-1])
    
    popped_item = LIST_C.pop(3)
    print(f'Deleted 4th item(index=3)={popped_item} from list C: {LIST_C}')
    
    LIST_C.insert(5,LIST_A)
    print(f'Insert items from list A to list C start from pos5(index=4): {LIST_A}')
    
    LIST_B.sort()
    print('sorting List B:',LIST_B)

    """
    updated on Mar 23th 22:54
    课上写的有点问题，重写了
    print('number of similar items in the list B: ',sum([1 if LIST_B[i] in LIST_B[i+1:] else 0 for i in range(len(LIST_B))]))
    """
    TEMP_DICT_SIMCOUNTER = {}
    for i in LIST_B: 
        if i in TEMP_DICT_SIMCOUNTER: TEMP_DICT_SIMCOUNTER[i]+=1 
        else: TEMP_DICT_SIMCOUNTER[i]=1

    print('number of similar items in the list B: ',*[f'{i}:{TEMP_DICT_SIMCOUNTER[i]} times ' if TEMP_DICT_SIMCOUNTER[i]>1 else "" for i in TEMP_DICT_SIMCOUNTER.keys()],sep='')
    
    print('==End Of Ex4==')
    return 0

if __name__ == '__main__':
    main()