Python Nested Loops

Loop Satellite

Nested Loops

Loop inside a loop to handle matrices, cartesian products, or grouped data—but keep complexity under control.

Study examplesKnow when to refactor

Examples

for row in matrix:
    for value in row:
        process(value)

for user in users:
    for order in user.orders:
        ...

Refactoring

• Extract inner loops into helper functions.
• Use itertools.product for cartesian products.
• Consider comprehensions or vectorized libraries (NumPy) for heavy numeric work.

Next up in your learning path

Nested lists

Structure the data you iterate over.

Companion

Loop control

Manage break/continue inside nested loops.

Practice

Comprehensions

Convert manageable nested loops into nested comprehensions.

Tip