{"action":"closed","issue":{"url":"https://api.github.com/repos/convexopt/gpkit/issues/407","labels_url":"https://api.github.com/repos/convexopt/gpkit/issues/407/labels{/name}","comments_url":"https://api.github.com/repos/convexopt/gpkit/issues/407/comments","events_url":"https://api.github.com/repos/convexopt/gpkit/issues/407/events","html_url":"https://github.com/convexopt/gpkit/issues/407","id":107613018,"number":407,"title":"exps is a list","user":{"login":"pgkirsch","id":8702579,"avatar_url":"https://avatars.githubusercontent.com/u/8702579?v=3","gravatar_id":"","url":"https://api.github.com/users/pgkirsch","html_url":"https://github.com/pgkirsch","followers_url":"https://api.github.com/users/pgkirsch/followers","following_url":"https://api.github.com/users/pgkirsch/following{/other_user}","gists_url":"https://api.github.com/users/pgkirsch/gists{/gist_id}","starred_url":"https://api.github.com/users/pgkirsch/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pgkirsch/subscriptions","organizations_url":"https://api.github.com/users/pgkirsch/orgs","repos_url":"https://api.github.com/users/pgkirsch/repos","events_url":"https://api.github.com/users/pgkirsch/events{/privacy}","received_events_url":"https://api.github.com/users/pgkirsch/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":{"login":"pgkirsch","id":8702579,"avatar_url":"https://avatars.githubusercontent.com/u/8702579?v=3","gravatar_id":"","url":"https://api.github.com/users/pgkirsch","html_url":"https://github.com/pgkirsch","followers_url":"https://api.github.com/users/pgkirsch/followers","following_url":"https://api.github.com/users/pgkirsch/following{/other_user}","gists_url":"https://api.github.com/users/pgkirsch/gists{/gist_id}","starred_url":"https://api.github.com/users/pgkirsch/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pgkirsch/subscriptions","organizations_url":"https://api.github.com/users/pgkirsch/orgs","repos_url":"https://api.github.com/users/pgkirsch/repos","events_url":"https://api.github.com/users/pgkirsch/events{/privacy}","received_events_url":"https://api.github.com/users/pgkirsch/received_events","type":"User","site_admin":false},"milestone":null,"comments":1,"created_at":"2015-09-21T22:43:47Z","updated_at":"2015-09-22T14:26:09Z","closed_at":"2015-09-22T14:26:09Z","body":"```python\r\nIn [1]: from gpkit.shortcuts import *\r\n\r\nIn [2]: x = Var('x')\r\n\r\nIn [3]: m = Model(x, [x >= 1])\r\n\r\nIn [4]: m.solve()\r\n\r\nIn [5]: m.program.cost.exps\r\nOut[5]: [{x: 1}]\r\n```\r\n\r\nMy understanding is that this is outdated and that `exps` should always be a tuple these days.\r\n\r\n```python\r\nIn [1]: from gpkit.shortcuts import *\r\nOptional Python units library (Pint) not installed; unit support disabled.\r\n\r\nIn [2]: x = Var('x')\r\n\r\nIn [3]: x.e\r\nx.exp   x.exps  \r\n\r\nIn [3]: x.exps \r\nOut[3]: ({x: 1},)\r\n```\r\n\r\nAnyway, this causes an issue in line ~364 of nominals.py\r\n\r\n```python\r\n    # posynomial arithmetic\r\n    def __add__(self, other):\r\n        if isinstance(other, Numbers):\r\n            if other == 0:\r\n                return Signomial(self.exps, self.cs)\r\n            else:\r\n                print self.exps\r\n                return Signomial(self.exps + ({},), # TypeError: can only concatenate list (not \"tuple\") to list\r\n                                 self.cs.tolist() + [other])\r\n```\r\n"}}