{"id":3230,"date":"2020-06-17T10:35:38","date_gmt":"2020-06-17T05:05:38","guid":{"rendered":"http:\/\/www.pythonpool.com\/?p=3230"},"modified":"2026-07-14T19:49:42","modified_gmt":"2026-07-14T14:19:42","slug":"python-2d-list","status":"publish","type":"post","link":"https:\/\/www.pythonpool.com\/python-2d-list\/","title":{"rendered":"Python 2D Lists: Create, Index, Copy, Flatten, and Loop"},"content":{"rendered":"

Quick answer:<\/strong> A Python 2D list is a list of row lists. Create independent rows with a list comprehension, such as [[0] * columns for _ in range(rows)]<\/code>; avoid [[0] * columns] * rows<\/code> because every row then refers to the same list.<\/p>\n

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Nested lists are flexible, but independent rows and an explicit shape contract make their mutations predictable.<\/figcaption><\/figure>\n

A two-dimensional list is a convenient built-in representation for a small table, grid, board, or matrix-like value. The first index selects a row and the second selects a value inside that row. Python lists are mutable, so updating a cell changes the structure in place.<\/p>\n

The official Python data structures tutorial<\/a> explains list operations. A 2D list is not a special array type; it is a nested collection, and rows may even have different lengths unless your program enforces a rectangular shape.<\/p>\n

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