Python Generators and Iterators

Create generators/iterators for: [DESCRIBE YOUR USE CASE]

Data processing needs:
- Input size: [SMALL/LARGE/INFINITE]
- Processing type: [TRANSFORM/FILTER/AGGREGATE]
- Memory constraints: [LIMITED/FLEXIBLE]

Provide:
1. Generator functions (yield)
2. Generator expressions
3. Custom iterator classes
4. Infinite generators
5. Generator pipelines
6. send() and throw() methods
7. yield from for delegation
8. Async generators (async yield)
9. itertools usage
10. Memory comparison vs lists
11. Error handling in generators
12. Testing generators
13. Real-world examples