What are some examples of lazy evaluation in Python?

What are some examples of lazy evaluation in Python?

Lazy evaluation is a programming technique where an expression is not evaluated until its value is needed. In Python, this can be seen in generators and the map() function.

Can you explain how generators work in this context?

Sure! Generators in Python use the yield keyword to produce a sequence of values lazily. This means they generate values on-the-fly and only when requested, which saves memory.

What about the map() function? How does it demonstrate lazy evaluation?

The map() function applies a given function to all items in an iterable and returns a map object, which is an iterator. The values are computed only when you iterate over the map object.

Can you give me a code example of using a generator?

Certainly! Here's a simple generator function:

def count_up_to(n):
    count = 1
    while count <= n:
        yield count
        count += 1

You can use it like this:

for number in count_up_to(5):
    print(number)