Answer 1

Map basically applies an operation (a function or lambda) to each value of an array. For example:

arr = [1, 2, 3, 4 5]
newarr = list(map(lambda x: x*2, arr))
#newarr=[2, 4, 6, 8, 10]

The lambda takes a value x, in this case a member of the array, and returns x*2. Map applies this to all of the values, doubling them all.

Hope this clears stuff up. If not, wait for a response from a more seasoned Pythonist.