{"id":21734,"date":"2022-03-30T14:02:52","date_gmt":"2022-03-30T08:32:52","guid":{"rendered":"http:\/\/www.pythonpool.com\/?p=21734"},"modified":"2026-07-14T19:49:26","modified_gmt":"2026-07-14T14:19:26","slug":"python-copy-list","status":"publish","type":"post","link":"https:\/\/www.pythonpool.com\/python-copy-list\/","title":{"rendered":"Copy a List in Python: Slicing, copy(), and deepcopy()"},"content":{"rendered":"

Quick answer:<\/strong> Assignment creates another reference to a list. Use slicing, list(), or copy() for a shallow copy of the outer list, and use copy.deepcopy only when nested mutable objects must be independent and the ownership and performance costs are understood.<\/p>\n

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A shallow list copy duplicates the outer container but keeps references to nested objects; choose deep copying only when the nested ownership contract requires it.<\/figcaption><\/figure>\n

To copy a list in Python<\/strong>, use list.copy()<\/code>, slicing, or list()<\/code> for a shallow copy. Use copy.deepcopy()<\/code> only when the list contains nested mutable objects and you need the nested objects copied too.<\/p>\n

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copied = original.copy()<\/code><\/pre>\n<\/div>\n
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Contents<\/p>\nToggle<\/span><\/path><\/svg><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n