Creating a map from two arrays in Python

I have two arrays like [[0, 0], [0.2, 20],[1.1, 30], [3.1, 50]] and [0, 10, 20, 30, 40, 50] I need to create a map like {0: 0, 10: 0, 20: 0, 30: 0.2, 50: 0.2}. How can I do this in Python?