René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Add new gotcha","articleBody":"Hi,\n\nWhile running tests on my code I was doing something like:\n\n```python\nclass Data:\n    mylist = [1,2,3,4]\n\n\ndef test_function():\n    local_list = Data.mylist\n    local_list+=new_list\n\n    # Do stuff with \n```\n\nand there are multiple tests using `mylist`. This is going to modify the list instead of creating a new one, an unexpected behavior of `+=`.  This will let one test talk to the tests happening later. The safer approach is:\n\n```python\nclass Data:\n    mylist = [1,2,3,4]\n\n\ndef test_function():\n    local_list =new_list + Data.mylist\n\n    # Do stuff with \n```\n\nhere `+` will copy the list. Could you please add this case?\n\nCheers.","author":{"url":"https://github.com/acampove","@type":"Person","name":"acampove"},"datePublished":"2025-05-18T15:14:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/1158/python-guide/issues/1158"}