Lesson 48 of 55
9 mins readPython Packages, Modules & the 1; Convention
In Plain English
Perl namespaces are defined with `package PackageName;`. Modules are saved in `.pm` files and must end with a true return value (`1;`). Load them with `use Module;`.
Deep Dive: How It Works
package Namespace: Encloses variables and subroutines in a distinct namespace (e.g. `Math::Utils`).
The 1; Convention: Every `.pm` module file must evaluate to true at the bottom to signal successful compilation to the interpreter.
use vs require: `use` loads and compiles modules at compile-time; `require` loads at runtime.
@INC Array: List of directory paths Perl searches when locating modules.
Core Rules to Remember
Namespaces with package: Separates function names to avoid global pollution.
Mandatory 1; at End of File: Every Perl module must terminate with `1;`.
Live Interactive Example
Hit Run Code to see it liveDefining and Calling Namespaced Subroutines
Python 3.12
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Output Console
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How it works: Logger::log_info called the subroutine defined within the Logger package namespace.
Your Turn: Micro Challenge
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Micro Exercise
Call Namespaced Subroutine
- Define `package MathUtils { sub square { my $n = shift; return $n * $n; } }`
- In `package main;`, print `"Square: " . MathUtils::square(9) . "\n"`.
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Sandbox Output
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