Map

Learn how to use the function, "map", to transform iterables by applying a function to them.

map function

The map function applies a supplied function to a set of arguments. It returns an iterator to access the results.

map with one parameter

In this example, we will use map with a user-defined function, square, that takes one parameter.

Press + to interact
def square(x):
return x*x
a = [2, 5, 6]
m = map(square, a)
print(list(m))

The map function applies square to each element in a, returning the squared values via an iterator. On line 7, we convert m to a list and print it.

Lazy evaluation

This is perhaps a good time to revisit the idea of lazy evaluation. All the functions described so far use lazy evaluation. We will illustrate this by ...