{"action":"opened","issue":{"url":"https://api.github.com/repos/JukkaL/mypy/issues/1198","labels_url":"https://api.github.com/repos/JukkaL/mypy/issues/1198/labels{/name}","comments_url":"https://api.github.com/repos/JukkaL/mypy/issues/1198/comments","events_url":"https://api.github.com/repos/JukkaL/mypy/issues/1198/events","html_url":"https://github.com/JukkaL/mypy/issues/1198","id":129958541,"number":1198,"title":"Proposal: warn about implicit Any","user":{"login":"migel","id":3897227,"avatar_url":"https://avatars.githubusercontent.com/u/3897227?v=3","gravatar_id":"","url":"https://api.github.com/users/migel","html_url":"https://github.com/migel","followers_url":"https://api.github.com/users/migel/followers","following_url":"https://api.github.com/users/migel/following{/other_user}","gists_url":"https://api.github.com/users/migel/gists{/gist_id}","starred_url":"https://api.github.com/users/migel/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/migel/subscriptions","organizations_url":"https://api.github.com/users/migel/orgs","repos_url":"https://api.github.com/users/migel/repos","events_url":"https://api.github.com/users/migel/events{/privacy}","received_events_url":"https://api.github.com/users/migel/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-01-30T08:41:33Z","updated_at":"2016-01-30T08:41:33Z","closed_at":null,"body":"Add an option to warn when mypy implicitly infers the `Any` type (like the `--noImplicitAny` option of the TypeScript compiler). This should help in avoiding issues like:\r\n\r\n```python\r\nclass C:\r\n    def f(self) -> float:\r\n        return 5.0\r\n\r\n\r\nclass D(C):\r\n    def f(self): # mypy will not emit an error because it inferred the return type as Any\r\n        return 'x'\r\n```"}}