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Lists and Filtering Algorithms
What Are Lists in Python?
- A list is just an ordered collection of stuff like numbers, words, or even True/False values.
- Lists are mutable, meaning you can change them after creating them.
- Lists are written in square brackets
[].
Creating Lists
- You can throw a bunch of different types of things into one list, like a mix of numbers, text, or booleans.
Accessing List Items
- You can grab items from a list by using positive indexing (starting from 0) or negative indexing (starting from -1, counting from the end).
Changing Lists
- You can update things in a list, add new stuff, or remove things you don’t need anymore.
What Are Filtering Algorithms?
- Filtering algorithms help you make a new list by picking out things that meet certain conditions.
- Example: you could filter a list to just show even numbers or people older than a certain age.
Efficiency of Filtering
- Filtering means going through each item in the list one by one.
- The bigger the list, the longer it takes to filter through.
- This is called O(n) time complexity, which basically means the time it takes grows with the list size.