How to Use Python’s xrange and Range

xrange in Python 2

xrange generates numbers lazily, making it memory efficient for loops and large sequences. It doesn’t store the entire list in memory.

range in Python 2

range creates a list of numbers in memory, which can be inefficient for large ranges compared to xrange.

Python 3 Changes

In Python 3, range replaces xrange functionality, providing lazy evaluation for memory efficiency while maintaining list-like behavior.

Memory Efficiency

For large sequences, use xrange in Python 2 or range in Python 3 to conserve memory instead of creating a full list.

Conversion to List

Use list(range(start, stop)) in Python 3 if you need a full list from range for operations requiring list methods.

Migration Tips

Replace xrange with range when migrating Python 2 code to Python 3, as range now handles sequences lazily in Python 3.