Question

def flatten(1st): ""Takes a nested list and "flattens" it. >flatten([1, 2, 3]) [1, 2, 3] >>> x = [1, [2, 3], 4] >>> flatten (x) [1, 2, 3, 4] > x = [[1, [1, 1]], 1, [1, 1]] >>> flatten(x) [1, 1, 1, 1, 1, 1] >>> lst = [1, [[2], 3], 4, [5, 6]] >>> flatten (1st) [1, 2, 3, 4, 5, 6] пии "*** YOUR CODE HERE ***"

Can you also explain the functions and what they do please?

Answer 1

def flatten(lst):
    if type(lst) != list:  # item lst is not of type list
        return [lst]  # then put it inside a list and return it
    result = []  # create empty list as result
    for item in lst:  # go through each item in list
        result += flatten(item)  # flatten the item recursively and add the list to result list
    return result  # return the result list


print(flatten([1, 2, 3]))
print(flatten([1, [2, 3], 4]))
print(flatten([[1, [1, 1]], 1, [1, 1]]))
print(flatten([1, [[2], 3], 4, [5, 6]]))

[1, 2, 3] [1, 2, 3, 4] [1, 1, 1, 1, 1, 1] [1, 2, 3, 4, 5, 6] Process finished with exit code 0