Lesson 46 of 55
9 mins readPython Pattern Search: string.find, match & gmatch
In Plain English
`string.find` returns start/end match indices, `string.match` extracts pattern captures, and `string.gmatch` returns an iterator over all occurrences in a string.
Deep Dive: How It Works
string.find(s, pat [, init [, plain]]): Returns start and end indices of match.
string.match(s, pat): Returns the captures defined in parentheses `(...)`.
string.gmatch(s, pat): Iterator yielding captures in a `for` loop.
Core Rules to Remember
string.find Indices: Returns start and end character positions.
string.gmatch Iterator: Traverses all occurrences across a multi-token string.
Live Interactive Example
Hit Run Code to see it liveExtracting Words and Pairs with gmatch
Python 3.12
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Output Console
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How it works: gmatch extracted each pair and unpacked them into key and val.
Your Turn: Micro Challenge
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Micro Exercise
Count Words with gmatch
- Declare `local text = "Lua is fast and lightweight"`.
- Count all words using `for w in text:gmatch("%a+") do count = count + 1 end`.
- Print `"Word count: " .. count`.
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Sandbox Output
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