Сплющить 2 -й массив питона
arr_2d = [[1, 2, 3], [4, 5, 6]]
arr_1d = [el for arr in arr_2d for el in arr]
print(arr_1d) # [1, 2, 3, 4, 5, 6]
PeruTilli
arr_2d = [[1, 2, 3], [4, 5, 6]]
arr_1d = [el for arr in arr_2d for el in arr]
print(arr_1d) # [1, 2, 3, 4, 5, 6]