Puzzle 17 - Flatten the list and Count the Occurrences

You’ve been given a jumbled guest list where names are stored in a nested structure of lists within lists. Some guests appear more than once — that’s okay. Your goal is to unpack this structure into a flat list and count the occurrence of each item and display the output. This solution should work with any level of nesting.

Input & Expected Output

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Input List

Guests = ["John Doe","Jane Doe",["Emily Doe","John Doe","Michael Smith"],["sarah Johnson",["Michael Smith","David Brown","Alice Green"],"Bob White","Alice Green"]]

Try solving the question yourself! If you need help, click below to reveal the solution.

def occurance(lst):
    result = []
    for item in lst:
        if isinstance(item,list):
            result.extend(occurance(item))
        else:
           result.append(item)
    return result

unpacked = occurance(Guests)
final_dic ={}
for item in unpacked:
    if item in final_dic:
        final_dic[item] +=1
    else:
        final_dic[item] = 1
print("##  Input List  #####")
print(Guests)
print("##  OutPut #####")
display(final_dic)