I am just starting to learn python and was looking for a solution to build a multi-dimensional list. I want to understand how it works.


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And also, how does the way this (below code) is written actually creates the output? Is this just built into the language?




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Any help will be appreciated!

Multidimensional lists in pure Python are lists-of-lists. For a two-dimensional list a, e.g., a[0] is a list, a[1] is a list, and a[1][0] is an element. Your example creates a 4-element list where each element is also a 4-element list, functionally giving you a 4x4 2D list (although it's sort of up to you to interpret that as a 4x4 array; the language doesn't really know anything about that). The thing you've used there ([f(x) for x in iterable]) is called a "list comprehension", and is indeed a feature of the Python language. You can even use it to apply a function to every element of a list. For example, this will square the numbers from 0 to 9:

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If you're writing Python on a computer, and having big arrays on which you can perform fast math is important to you, numpy is a good solution to explore.