{"action":"created","issue":{"url":"https://api.github.com/repos/JukkaL/mypy/issues/815","labels_url":"https://api.github.com/repos/JukkaL/mypy/issues/815/labels{/name}","comments_url":"https://api.github.com/repos/JukkaL/mypy/issues/815/comments","events_url":"https://api.github.com/repos/JukkaL/mypy/issues/815/events","html_url":"https://github.com/JukkaL/mypy/issues/815","id":101772699,"number":815,"title":"mypy confused by defaultdict(list)","user":{"login":"MichalPokorny","id":714892,"avatar_url":"https://avatars.githubusercontent.com/u/714892?v=3","gravatar_id":"","url":"https://api.github.com/users/MichalPokorny","html_url":"https://github.com/MichalPokorny","followers_url":"https://api.github.com/users/MichalPokorny/followers","following_url":"https://api.github.com/users/MichalPokorny/following{/other_user}","gists_url":"https://api.github.com/users/MichalPokorny/gists{/gist_id}","starred_url":"https://api.github.com/users/MichalPokorny/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MichalPokorny/subscriptions","organizations_url":"https://api.github.com/users/MichalPokorny/orgs","repos_url":"https://api.github.com/users/MichalPokorny/repos","events_url":"https://api.github.com/users/MichalPokorny/events{/privacy}","received_events_url":"https://api.github.com/users/MichalPokorny/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/JukkaL/mypy/labels/bug","name":"bug","color":"fc2929"},{"url":"https://api.github.com/repos/JukkaL/mypy/labels/priority","name":"priority","color":"f7c6c7"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":5,"created_at":"2015-08-18T23:32:52Z","updated_at":"2015-12-14T04:46:10Z","closed_at":null,"body":"Source:\r\n```\r\nfrom collections import defaultdict\r\nx = defaultdict(list)\r\n```\r\n\r\nError:\r\n```\r\ntest.py:2: error: Argument 1 to \"defaultdict\" has incompatible type List[_T]; expected Callable[[], List[_T]]\r\ntest.py:2: error: Need type annotation for variable\r\n```"},"comment":{"url":"https://api.github.com/repos/JukkaL/mypy/issues/comments/164341646","html_url":"https://github.com/JukkaL/mypy/issues/815#issuecomment-164341646","issue_url":"https://api.github.com/repos/JukkaL/mypy/issues/815","id":164341646,"user":{"login":"gvanrossum","id":2894642,"avatar_url":"https://avatars.githubusercontent.com/u/2894642?v=3","gravatar_id":"","url":"https://api.github.com/users/gvanrossum","html_url":"https://github.com/gvanrossum","followers_url":"https://api.github.com/users/gvanrossum/followers","following_url":"https://api.github.com/users/gvanrossum/following{/other_user}","gists_url":"https://api.github.com/users/gvanrossum/gists{/gist_id}","starred_url":"https://api.github.com/users/gvanrossum/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gvanrossum/subscriptions","organizations_url":"https://api.github.com/users/gvanrossum/orgs","repos_url":"https://api.github.com/users/gvanrossum/repos","events_url":"https://api.github.com/users/gvanrossum/events{/privacy}","received_events_url":"https://api.github.com/users/gvanrossum/received_events","type":"User","site_admin":false},"created_at":"2015-12-14T04:46:10Z","updated_at":"2015-12-14T04:46:10Z","body":"How hard would this be? The majority of uses of defaultdict that I see have one of the builtins `set` or `list` as argument. (Also the error message seems wrong -- the argument is not a value of type `List[_T]`, it's a class representing that type.)"}}