Think in Python / CORE PATH

Scope & side effects

Local names help a function behave predictably across calls.

Avoid notebook state that makes a cell work only after an undocumented execution order.

Understand the idea

Local names help a function behave predictably across calls. Avoid notebook state that makes a cell work only after an undocumented execution order.

Work through the practice with a tiny fixture, predict the result before running it, and record one boundary case. Use the exit check as evidence before moving on.

What to learn

• Trace local versus module names.
• Pass configuration as a parameter.
• Return a new value rather than modifying a shared dict accidentally.

A small original example

def classify_copy(record, category):
    result = dict(record)
    result["category"] = category
    return result

Practice on your own data

Task 04: add a category to a copied record without changing the original.

Practice this lesson in the Python lab →

Common pitfalls

• A shallow copy does not clone nested mutable values.
• Mutable default arguments persist between calls.

Prerequisites

Functions & explicit contracts

Boot.dev chapter 4 · 01:16:12 ↗

Video and playlist companions

Choose one explanation for the concept, then attempt the practice. These are topic mappings, not a claim that every linked lesson covers every outcome.

Boot.dev · Python for Beginners

▶Watch preview

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كورس Python منحة ITI

▤▶Explore playlist

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Sources and further reading

• Boot.dev · Python for Beginners ↗User-selected YouTube course
• كورس Python منحة ITI ↗User-selected ITI playlist
• Harvard CS50P · lectures & problem sets ↗User-selected HarvardX CS50P course
• Python language tutorial ↗Official documentation

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