René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"line number for a return in a with block after 3.10 is that of the with, not the return statement","articleBody":"```python\r\ndef foo() -\u003e int:\r\n    with open('/dev/null') as devnull:\r\n        return 'a'\r\n```\r\n\r\nIn Python 3.10 onwards, the reported line number for the `return` statement is incorrect.\r\n\r\nPython main 3.12-main-ish not far from 3.11:\r\n\r\n```\r\n\u003e\u003e\u003e def foo() -\u003e int:\r\n...   with open('a') as f:\r\n...     return 'b'\r\n... \r\n\u003e\u003e\u003e dis.dis(foo)\r\n  1           0 RESUME                   0\r\n\r\n  2           2 LOAD_GLOBAL              1 (NULL + open)\r\n             14 LOAD_CONST               1 ('a')\r\n             16 CALL                     1\r\n             26 BEFORE_WITH\r\n             28 STORE_FAST               0 (f)\r\n\r\n  3          30 NOP\r\n\r\n  2          32 LOAD_CONST               0 (None)\r\n             34 LOAD_CONST               0 (None)\r\n             36 LOAD_CONST               0 (None)\r\n             38 CALL                     2\r\n             48 POP_TOP\r\n             50 LOAD_CONST               2 ('b')\r\n             52 RETURN_VALUE\r\n        \u003e\u003e   54 PUSH_EXC_INFO\r\n             56 WITH_EXCEPT_START\r\n             58 POP_JUMP_FORWARD_IF_TRUE     4 (to 68)\r\n             60 RERAISE                  2\r\n        \u003e\u003e   62 COPY                     3\r\n             64 POP_EXCEPT\r\n             66 RERAISE                  1\r\n        \u003e\u003e   68 POP_TOP\r\n             70 POP_EXCEPT\r\n             72 POP_TOP\r\n             74 POP_TOP\r\n             76 LOAD_CONST               0 (None)\r\n             78 RETURN_VALUE\r\nExceptionTable:\r\n  28 to 30 -\u003e 54 [1] lasti\r\n  54 to 60 -\u003e 62 [3] lasti\r\n  68 to 68 -\u003e 62 [3] lasti\r\n\u003e\u003e\u003e sys.version_info\r\nsys.version_info(major=3, minor=12, micro=0, releaselevel='alpha', serial=0)\r\n```\r\n\r\nThe only thing attributed to line 3 is a NOP.  The RETURN_VALUE of 'b' is listed as line 2. That is wrong.\r\n\r\nPython 3.9:\r\n\r\n```\r\n\u003e\u003e\u003e def foo() -\u003e int:\r\n...   with open('a') as f:\r\n...     return 'b'\r\n... \r\n\u003e\u003e\u003e dis.dis(foo)\r\n  2           0 LOAD_GLOBAL              0 (open)\r\n              2 LOAD_CONST               1 ('a')\r\n              4 CALL_FUNCTION            1\r\n              6 SETUP_WITH              18 (to 26)\r\n              8 STORE_FAST               0 (f)\r\n\r\n  3          10 POP_BLOCK\r\n             12 LOAD_CONST               0 (None)\r\n             14 DUP_TOP\r\n             16 DUP_TOP\r\n             18 CALL_FUNCTION            3\r\n             20 POP_TOP\r\n             22 LOAD_CONST               2 ('b')\r\n             24 RETURN_VALUE\r\n        \u003e\u003e   26 WITH_EXCEPT_START\r\n             28 POP_JUMP_IF_TRUE        32\r\n             30 RERAISE\r\n        \u003e\u003e   32 POP_TOP\r\n             34 POP_TOP\r\n             36 POP_TOP\r\n             38 POP_EXCEPT\r\n             40 POP_TOP\r\n             42 LOAD_CONST               0 (None)\r\n             44 RETURN_VALUE\r\n\u003e\u003e\u003e sys.version_info\r\nsys.version_info(major=3, minor=9, micro=12, releaselevel='final', serial=0)\r\n```\r\n\r\nNoticed by @martindemello working on a 3.10 error attribution bug in pytype.","author":{"url":"https://github.com/gpshead","@type":"Person","name":"gpshead"},"datePublished":"2022-06-18T00:05:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/93975/cpython/issues/93975"}