Strings as Data Structures

In Part 1 (Module 2: Variables & Data Types), we learned about strings as a text data type — how to create text using quotes, combine sentences with +, check total length using len(), and convert between types.

In Part 2, we explore strings as an ordered collection of characters. Instead of viewing a string as a single chunk of text, Python allows us to look inside it as a sequence of individual letters arranged in a specific order, where every character has its own position.

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The Power of String Manipulation

Because strings are structured sequences of characters, Python lets us manipulate them in incredibly powerful ways:

1. Grab individual letters (Indexing): Get any specific character using its position number. For example, grabbing "P" from "Python" using word[0].
2. Cut out sections of text (Slicing): Extract a whole slice of a string. For example, grabbing "Py" from "Python" using word[0:2].
3. Clean up messy input (Stripping): Instantly remove accidental spaces typed by users at the beginning or end of text.
4. Search and Replace: Find out if a word exists inside a long paragraph, or replace specific words automatically.
5. Split and Join: Break a sentence into separate words, or glue separate words back together into a single string.

In the next two lessons, we will learn how to use these features step-by-step!

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Quick Summary

• String as Sequence: Strings are ordered sequences of characters where each letter occupies a fixed index position.
• Core Manipulations: Python provides indexing (single characters), slicing (sub-strings), searching, splitting, and joining.
• Immutability: Once created in memory, characters inside a string cannot be modified directly in place.

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What's Next?

Let's dive into String Indexing & Slicing to learn how to grab specific characters and slices of text in the next lesson!