create and add elements to 2d array in python code example

Example 1: python append to 2d array

temp_list = [[], [], [], []]
temp_list[0].append("a1")
temp_list[1].append("a2")
temp_list[2].append("a3")
temp_list[3].append("a4")

Example 2: python append row to 2d array

new_row.append([])