Lazy evaluation in Python delays the evaluation of expressions until their values are needed. It enables infinite data structures by lazily evaluating sequences, abstracts control structures using generators and generator expressions that follow the iterator protocol. Lazy evaluation provides performance benefits in both computation time and memory usage.

1. Lazy evaluation in Python
By Rahul Pydimukkala (rahulpyd@gmail.com)
BangPypers meetup (18th
Feb.,2017)

2. Lazy evaluation in Python
What is lazy evaluation?

3. Lazy evaluation in Python
Delay the evaluation
of an expression
until its value is needed.

4. Lazy evaluation in Python
Why?
- Enables infinite data structures
- Control structures as abstractions
- Performance benefits – computational and space

5. Lazy evaluation in Python
Why infinite data structures?
Lazy sequences

6. Lazy evaluation in Python
Abstracting out control structures

7. Lazy evaluation in Python
Generators

8. Lazy evaluation in Python
Generator expressions (genexps)

9. Lazy evaluation in Python
Iterator protocol
Iterator object
Iterables