The installer for Windows creates file associations inTools/msi/launcher/launcher_reg.wxs that identify ".py[w]" files as text/plain.This is inconsistent with the mimetypes module, which uses text/x-python, and may cause some applications to assume that calling ShellExecute on a .py file will open a text editor rather than executing the script.We should update the MIME type to text/x-python. This can be backported, as the change is in the launcher and isn't tied to the usual upgrade paths anyway.

The most likely negative potential impact of this would be for any users who have added additional verbs based on the content type. I don't recall whether we set PerceivedType or not, but that can probably stay.I'm not aware of any applications (besides Windows itself) that set verbs based on content type rather than extensions, so I doubt anyone will be too upset.

New changeset8c862e51248c5ebfec787badec88eb58c9267e1e by Zackery Spytz in branch 'master':bpo-39631: Fix file association MIME type in the Windows installer (GH-20205)https://github.com/python/cpython/commit/8c862e51248c5ebfec787badec88eb58c9267e1e

Actually, now that I've gone and hit merge, I've changed my mind about the NEWS entry. I'll add it.

New changesetc06983bc30e02700552c91be45559ca27fabc08e by Miss Islington (bot) in branch '3.9':bpo-39631: Fix file association MIME type in the Windows installer (GH-20205)https://github.com/python/cpython/commit/c06983bc30e02700552c91be45559ca27fabc08e

New changeset076da79bc75b9aac8b7bc9685253fa7162c25698 by Miss Islington (bot) in branch '3.7':bpo-39631: Fix file association MIME type in the Windows installer (GH-20205)https://github.com/python/cpython/commit/076da79bc75b9aac8b7bc9685253fa7162c25698

New changeset46fc3ec056ff7ce65e9b96f14bd0b06aa1d0c62d by Miss Islington (bot) in branch '3.8':bpo-39631: Fix file association MIME type in the Windows installer (GH-20205)https://github.com/python/cpython/commit/46fc3ec056ff7ce65e9b96f14bd0b06aa1d0c62d

New changeset92327a9913150f5bb55b2727a2c5d50f9b7b6e55 by Steve Dower in branch 'master':bpo-39631: Adds NEWS entry (GH-20227)https://github.com/python/cpython/commit/92327a9913150f5bb55b2727a2c5d50f9b7b6e55

New changeset67bbb5d4381b6121a4f61ba945c58056e5894846 by Miss Islington (bot) in branch '3.7':bpo-39631: Adds NEWS entry (GH-20227)https://github.com/python/cpython/commit/67bbb5d4381b6121a4f61ba945c58056e5894846

New changeset381ceeaa5980643fa1f958f112f373d7a197e6e8 by Miss Islington (bot) in branch '3.8':bpo-39631: Adds NEWS entry (GH-20227)https://github.com/python/cpython/commit/381ceeaa5980643fa1f958f112f373d7a197e6e8

New changeset1e5cf949ce36b6fe45db0e5e4a26c856c3b44278 by Miss Islington (bot) in branch '3.9':[3.9]bpo-39631: Adds NEWS entry (GH-20227) (GH-20241)https://github.com/python/cpython/commit/1e5cf949ce36b6fe45db0e5e4a26c856c3b44278