What is import?

Import is a way to bring code that lives in another file or library into the current program so you can use its functions, classes, or variables without rewriting them.

Let's break it down

  • Think of your code as a toolbox.
  • An import statement opens another toolbox (a module or package) and lets you pick the tools you need.
  • In most languages you write a single line like import math (Python) or import { readFile } from 'fs' (JavaScript) to do this.

Why does it matter?

Import keeps your code short, organized, and reusable. It lets many developers share useful code, so you don’t have to reinvent the wheel each time you start a new project.

Where is it used?

  • Python scripts (import os, import pandas)
  • JavaScript/Node.js (import express from 'express')
  • Java (import java.util.List;)
  • C# (using System;)
  • Any language that supports modules, packages, or libraries.

Good things about it

  • Reusability: Use proven code written by others.
  • Readability: Clear statements show which external tools the file depends on.
  • Maintainability: Update a library in one place and all imports get the new version.
  • Namespace control: You can import only what you need, avoiding name clashes.

Not-so-good things

  • Dependency bloat: Importing many large libraries can make the program slower to start or increase file size.
  • Version conflicts: Different libraries may require incompatible versions of the same dependency.
  • Hidden complexity: Over‑using imports can make it hard to trace where a function actually comes from, especially for beginners.
  • Runtime errors: If an imported module is missing or mis‑named, the program will crash at load time.