René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`dis.dis()` reports line numbers where there are none.","articleBody":"Take this example function from https://github.com/python/cpython/issues/107901:\r\n```\r\ndef f():\r\n   for i in range(30000000):\r\n      if not i%1000000:\r\n          pass\r\n```\r\n`dis.dis` produces the following output:\r\n```\r\n  1           0 RESUME                   0\r\n\r\n  2           2 LOAD_GLOBAL              1 (range + NULL)\r\n             12 LOAD_CONST               1 (30000000)\r\n             14 CALL                     1\r\n             22 GET_ITER\r\n        \u003e\u003e   24 FOR_ITER                14 (to 56)\r\n             28 STORE_FAST               0 (i)\r\n\r\n  3          30 LOAD_FAST                0 (i)\r\n             32 LOAD_CONST               2 (1000000)\r\n             34 BINARY_OP                6 (%)\r\n             38 TO_BOOL\r\n             46 POP_JUMP_IF_FALSE        2 (to 52)\r\n             48 JUMP_BACKWARD           14 (to 24)\r\n\r\n  4     \u003e\u003e   52 JUMP_BACKWARD           16 (to 24)\r\n\r\n  2     \u003e\u003e   56 END_FOR\r\n             58 RETURN_CONST             0 (None)\r\n```\r\nWhich has incorrect line numbers.\r\nThe issue is not that the line numbers are wrong, but that you can't tell from the `dis` output.\r\nThe whole point of `dis` is show what is going on at the bytecode level, so it is failing if it gives wrong line numbers.\r\nThe actual line numbers can be see from `co_lines()`\r\n```\r\n\u003e\u003e\u003e list(f.__code__.co_lines())\r\n[(0, 2, 1), (2, 30, 2), (30, 48, 3), (48, 52, None), (52, 56, 4), (56, 60, 2)]\r\n```\r\n\r\nThe correct output should be:\r\n```\r\n   1           0 RESUME                   0\r\n\r\n   2           2 LOAD_GLOBAL              1 (range + NULL)\r\n              12 LOAD_CONST               1 (30000000)\r\n              14 CALL                     1\r\n              22 GET_ITER\r\n         \u003e\u003e   24 FOR_ITER                14 (to 56)\r\n              28 STORE_FAST               0 (i)\r\n\r\n   3          30 LOAD_FAST                0 (i)\r\n              32 LOAD_CONST               2 (1000000)\r\n              34 BINARY_OP                6 (%)\r\n              38 TO_BOOL\r\n              46 POP_JUMP_IF_FALSE        2 (to 52)\r\nNone          48 JUMP_BACKWARD           14 (to 24)\r\n\r\n   4     \u003e\u003e   52 JUMP_BACKWARD           16 (to 24)\r\n\r\n   2     \u003e\u003e   56 END_FOR\r\n              58 RETURN_CONST             0 (None)\r\n```\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-107988\n* gh-108479\n* gh-108478\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/markshannon","@type":"Person","name":"markshannon"},"datePublished":"2023-08-14T09:03:02.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/107932/cpython/issues/107932"}