{"action":"closed","number":9239,"pull_request":{"url":"https://api.github.com/repos/pydata/pandas/pulls/9239","id":27270939,"html_url":"https://github.com/pydata/pandas/pull/9239","diff_url":"https://github.com/pydata/pandas/pull/9239.diff","patch_url":"https://github.com/pydata/pandas/pull/9239.patch","issue_url":"https://api.github.com/repos/pydata/pandas/issues/9239","number":9239,"state":"closed","locked":false,"title":"API: Add DataFrame.assign method","user":{"login":"TomAugspurger","id":1312546,"avatar_url":"https://avatars.githubusercontent.com/u/1312546?v=3","gravatar_id":"","url":"https://api.github.com/users/TomAugspurger","html_url":"https://github.com/TomAugspurger","followers_url":"https://api.github.com/users/TomAugspurger/followers","following_url":"https://api.github.com/users/TomAugspurger/following{/other_user}","gists_url":"https://api.github.com/users/TomAugspurger/gists{/gist_id}","starred_url":"https://api.github.com/users/TomAugspurger/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TomAugspurger/subscriptions","organizations_url":"https://api.github.com/users/TomAugspurger/orgs","repos_url":"https://api.github.com/users/TomAugspurger/repos","events_url":"https://api.github.com/users/TomAugspurger/events{/privacy}","received_events_url":"https://api.github.com/users/TomAugspurger/received_events","type":"User","site_admin":false},"body":"Closes https://github.com/pydata/pandas/issues/9229\r\n\r\nsignature: `DataFrame.transform(**kwargs)`\r\n\r\n- the keyword is the name of the new column (existing columns are overwritten if there's a name conflict, as in dplyr)\r\n- the value is either\r\n  - called on self if it's callable. The callable should be a function of 1 argument, the DataFrame being called on.\r\n  - inserted otherwise\r\n\r\n\r\n```python\r\nIn [7]: df.head()\r\nOut[7]: \r\n   sepal_length  sepal_width  petal_length  petal_width species\r\n0           5.1          3.5           1.4          0.2  setosa\r\n1           4.9          3.0           1.4          0.2  setosa\r\n2           4.7          3.2           1.3          0.2  setosa\r\n3           4.6          3.1           1.5          0.2  setosa\r\n4           5.0          3.6           1.4          0.2  setosa\r\n\r\nIn [8]: (df.query('species == \"virginica\"')\r\n           .transform(sepal_ratio=lambda x: x.sepal_length / x.sepal_width)\r\n           .head())\r\nOut[8]: \r\n     sepal_length  sepal_width  petal_length  petal_width    species  \\\r\n100           6.3          3.3           6.0          2.5  virginica   \r\n101           5.8          2.7           5.1          1.9  virginica   \r\n102           7.1          3.0           5.9          2.1  virginica   \r\n103           6.3          2.9           5.6          1.8  virginica   \r\n104           6.5          3.0           5.8          2.2  virginica   \r\n\r\n     sepal_ratio  \r\n100     1.909091  \r\n101     2.148148  \r\n102     2.366667  \r\n103     2.172414  \r\n104     2.166667  \r\n```\r\n\r\nMy question now is\r\n\r\n- How strict should we be on the shape of the `transformed` DataFrame? Should we do any kind of checking on the index or columns?\r\n","created_at":"2015-01-13T13:32:24Z","updated_at":"2015-03-01T14:51:09Z","closed_at":"2015-03-01T14:51:09Z","merged_at":"2015-03-01T14:51:09Z","merge_commit_sha":"6883e7087fb343785bd8a503850ab64e32fdf688","assignee":null,"milestone":{"url":"https://api.github.com/repos/pydata/pandas/milestones/25","html_url":"https://github.com/pydata/pandas/milestones/0.16.0","labels_url":"https://api.github.com/repos/pydata/pandas/milestones/25/labels","id":569113,"number":25,"title":"0.16.0","description":"after 0.15 of course!","creator":{"login":"jreback","id":953992,"avatar_url":"https://avatars.githubusercontent.com/u/953992?v=3","gravatar_id":"","url":"https://api.github.com/users/jreback","html_url":"https://github.com/jreback","followers_url":"https://api.github.com/users/jreback/followers","following_url":"https://api.github.com/users/jreback/following{/other_user}","gists_url":"https://api.github.com/users/jreback/gists{/gist_id}","starred_url":"https://api.github.com/users/jreback/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jreback/subscriptions","organizations_url":"https://api.github.com/users/jreback/orgs","repos_url":"https://api.github.com/users/jreback/repos","events_url":"https://api.github.com/users/jreback/events{/privacy}","received_events_url":"https://api.github.com/users/jreback/received_events","type":"User","site_admin":false},"open_issues":808,"closed_issues":303,"state":"open","created_at":"2014-02-14T03:31:22Z","updated_at":"2015-03-01T14:51:09Z","due_on":"2015-03-10T04:00:00Z","closed_at":null},"commits_url":"https://api.github.com/repos/pydata/pandas/pulls/9239/commits","review_comments_url":"https://api.github.com/repos/pydata/pandas/pulls/9239/comments","review_comment_url":"https://api.github.com/repos/pydata/pandas/pulls/comments{/number}","comments_url":"https://api.github.com/repos/pydata/pandas/issues/9239/comments","statuses_url":"https://api.github.com/repos/pydata/pandas/statuses/6a5bd899833ee72678e6c61b9e22ba1b24c19878","head":{"label":"TomAugspurger:dfTransform","ref":"dfTransform","sha":"6a5bd899833ee72678e6c61b9e22ba1b24c19878","user":{"login":"TomAugspurger","id":1312546,"avatar_url":"https://avatars.githubusercontent.com/u/1312546?v=3","gravatar_id":"","url":"https://api.github.com/users/TomAugspurger","html_url":"https://github.com/TomAugspurger","followers_url":"https://api.github.com/users/TomAugspurger/followers","following_url":"https://api.github.com/users/TomAugspurger/following{/other_user}","gists_url":"https://api.github.com/users/TomAugspurger/gists{/gist_id}","starred_url":"https://api.github.com/users/TomAugspurger/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TomAugspurger/subscriptions","organizations_url":"https://api.github.com/users/TomAugspurger/orgs","repos_url":"https://api.github.com/users/TomAugspurger/repos","events_url":"https://api.github.com/users/TomAugspurger/events{/privacy}","received_events_url":"https://api.github.com/users/TomAugspurger/received_events","type":"User","site_admin":false},"repo":{"id":9450481,"name":"pandas","full_name":"TomAugspurger/pandas","owner":{"login":"TomAugspurger","id":1312546,"avatar_url":"https://avatars.githubusercontent.com/u/1312546?v=3","gravatar_id":"","url":"https://api.github.com/users/TomAugspurger","html_url":"https://github.com/TomAugspurger","followers_url":"https://api.github.com/users/TomAugspurger/followers","following_url":"https://api.github.com/users/TomAugspurger/following{/other_user}","gists_url":"https://api.github.com/users/TomAugspurger/gists{/gist_id}","starred_url":"https://api.github.com/users/TomAugspurger/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TomAugspurger/subscriptions","organizations_url":"https://api.github.com/users/TomAugspurger/orgs","repos_url":"https://api.github.com/users/TomAugspurger/repos","events_url":"https://api.github.com/users/TomAugspurger/events{/privacy}","received_events_url":"https://api.github.com/users/TomAugspurger/received_events","type":"User","site_admin":false},"private":false,"html_url":"https://github.com/TomAugspurger/pandas","description":"Flexible and powerful data analysis / manipulation library for Python, providing labeled data structures similar to R data.frame objects, statistical functions, and much more","fork":true,"url":"https://api.github.com/repos/TomAugspurger/pandas","forks_url":"https://api.github.com/repos/TomAugspurger/pandas/forks","keys_url":"https://api.github.com/repos/TomAugspurger/pandas/keys{/key_id}","collaborators_url":"https://api.github.com/repos/TomAugspurger/pandas/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/TomAugspurger/pandas/teams","hooks_url":"https://api.github.com/repos/TomAugspurger/pandas/hooks","issue_events_url":"https://api.github.com/repos/TomAugspurger/pandas/issues/events{/number}","events_url":"https://api.github.com/repos/TomAugspurger/pandas/events","assignees_url":"https://api.github.com/repos/TomAugspurger/pandas/assignees{/user}","branches_url":"https://api.github.com/repos/TomAugspurger/pandas/branches{/branch}","tags_url":"https://api.github.com/repos/TomAugspurger/pandas/tags","blobs_url":"https://api.github.com/repos/TomAugspurger/pandas/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/TomAugspurger/pandas/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/TomAugspurger/pandas/git/refs{/sha}","trees_url":"https://api.github.com/repos/TomAugspurger/pandas/git/trees{/sha}","statuses_url":"https://api.github.com/repos/TomAugspurger/pandas/statuses/{sha}","languages_url":"https://api.github.com/repos/TomAugspurger/pandas/languages","stargazers_url":"https://api.github.com/repos/TomAugspurger/pandas/stargazers","contributors_url":"https://api.github.com/repos/TomAugspurger/pandas/contributors","subscribers_url":"https://api.github.com/repos/TomAugspurger/pandas/subscribers","subscription_url":"https://api.github.com/repos/TomAugspurger/pandas/subscription","commits_url":"https://api.github.com/repos/TomAugspurger/pandas/commits{/sha}","git_commits_url":"https://api.github.com/repos/TomAugspurger/pandas/git/commits{/sha}","comments_url":"https://api.github.com/repos/TomAugspurger/pandas/comments{/number}","issue_comment_url":"https://api.github.com/repos/TomAugspurger/pandas/issues/comments{/number}","contents_url":"https://api.github.com/repos/TomAugspurger/pandas/contents/{+path}","compare_url":"https://api.github.com/repos/TomAugspurger/pandas/compare/{base}...{head}","merges_url":"https://api.github.com/repos/TomAugspurger/pandas/merges","archive_url":"https://api.github.com/repos/TomAugspurger/pandas/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/TomAugspurger/pandas/downloads","issues_url":"https://api.github.com/repos/TomAugspurger/pandas/issues{/number}","pulls_url":"https://api.github.com/repos/TomAugspurger/pandas/pulls{/number}","milestones_url":"https://api.github.com/repos/TomAugspurger/pandas/milestones{/number}","notifications_url":"https://api.github.com/repos/TomAugspurger/pandas/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/TomAugspurger/pandas/labels{/name}","releases_url":"https://api.github.com/repos/TomAugspurger/pandas/releases{/id}","created_at":"2013-04-15T14:23:40Z","updated_at":"2014-06-11T15:10:22Z","pushed_at":"2015-03-01T13:47:10Z","git_url":"git://github.com/TomAugspurger/pandas.git","ssh_url":"git@github.com:TomAugspurger/pandas.git","clone_url":"https://github.com/TomAugspurger/pandas.git","svn_url":"https://github.com/TomAugspurger/pandas","homepage":"http://pandas.pydata.org","size":48394,"stargazers_count":0,"watchers_count":0,"language":"Python","has_issues":false,"has_downloads":true,"has_wiki":true,"has_pages":false,"forks_count":0,"mirror_url":null,"open_issues_count":0,"forks":0,"open_issues":0,"watchers":0,"default_branch":"master"}},"base":{"label":"pydata:master","ref":"master","sha":"fc843d34edc5d538c9a80034d71e22e95ca08f4a","user":{"login":"pydata","id":1284191,"avatar_url":"https://avatars.githubusercontent.com/u/1284191?v=3","gravatar_id":"","url":"https://api.github.com/users/pydata","html_url":"https://github.com/pydata","followers_url":"https://api.github.com/users/pydata/followers","following_url":"https://api.github.com/users/pydata/following{/other_user}","gists_url":"https://api.github.com/users/pydata/gists{/gist_id}","starred_url":"https://api.github.com/users/pydata/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pydata/subscriptions","organizations_url":"https://api.github.com/users/pydata/orgs","repos_url":"https://api.github.com/users/pydata/repos","events_url":"https://api.github.com/users/pydata/events{/privacy}","received_events_url":"https://api.github.com/users/pydata/received_events","type":"Organization","site_admin":false},"repo":{"id":858127,"name":"pandas","full_name":"pydata/pandas","owner":{"login":"pydata","id":1284191,"avatar_url":"https://avatars.githubusercontent.com/u/1284191?v=3","gravatar_id":"","url":"https://api.github.com/users/pydata","html_url":"https://github.com/pydata","followers_url":"https://api.github.com/users/pydata/followers","following_url":"https://api.github.com/users/pydata/following{/other_user}","gists_url":"https://api.github.com/users/pydata/gists{/gist_id}","starred_url":"https://api.github.com/users/pydata/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pydata/subscriptions","organizations_url":"https://api.github.com/users/pydata/orgs","repos_url":"https://api.github.com/users/pydata/repos","events_url":"https://api.github.com/users/pydata/events{/privacy}","received_events_url":"https://api.github.com/users/pydata/received_events","type":"Organization","site_admin":false},"private":false,"html_url":"https://github.com/pydata/pandas","description":"Flexible and powerful data analysis / manipulation library for Python, providing labeled data structures similar to R data.frame objects, statistical functions, and much more","fork":false,"url":"https://api.github.com/repos/pydata/pandas","forks_url":"https://api.github.com/repos/pydata/pandas/forks","keys_url":"https://api.github.com/repos/pydata/pandas/keys{/key_id}","collaborators_url":"https://api.github.com/repos/pydata/pandas/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/pydata/pandas/teams","hooks_url":"https://api.github.com/repos/pydata/pandas/hooks","issue_events_url":"https://api.github.com/repos/pydata/pandas/issues/events{/number}","events_url":"https://api.github.com/repos/pydata/pandas/events","assignees_url":"https://api.github.com/repos/pydata/pandas/assignees{/user}","branches_url":"https://api.github.com/repos/pydata/pandas/branches{/branch}","tags_url":"https://api.github.com/repos/pydata/pandas/tags","blobs_url":"https://api.github.com/repos/pydata/pandas/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/pydata/pandas/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/pydata/pandas/git/refs{/sha}","trees_url":"https://api.github.com/repos/pydata/pandas/git/trees{/sha}","statuses_url":"https://api.github.com/repos/pydata/pandas/statuses/{sha}","languages_url":"https://api.github.com/repos/pydata/pandas/languages","stargazers_url":"https://api.github.com/repos/pydata/pandas/stargazers","contributors_url":"https://api.github.com/repos/pydata/pandas/contributors","subscribers_url":"https://api.github.com/repos/pydata/pandas/subscribers","subscription_url":"https://api.github.com/repos/pydata/pandas/subscription","commits_url":"https://api.github.com/repos/pydata/pandas/commits{/sha}","git_commits_url":"https://api.github.com/repos/pydata/pandas/git/commits{/sha}","comments_url":"https://api.github.com/repos/pydata/pandas/comments{/number}","issue_comment_url":"https://api.github.com/repos/pydata/pandas/issues/comments{/number}","contents_url":"https://api.github.com/repos/pydata/pandas/contents/{+path}","compare_url":"https://api.github.com/repos/pydata/pandas/compare/{base}...{head}","merges_url":"https://api.github.com/repos/pydata/pandas/merges","archive_url":"https://api.github.com/repos/pydata/pandas/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/pydata/pandas/downloads","issues_url":"https://api.github.com/repos/pydata/pandas/issues{/number}","pulls_url":"https://api.github.com/repos/pydata/pandas/pulls{/number}","milestones_url":"https://api.github.com/repos/pydata/pandas/milestones{/number}","notifications_url":"https://api.github.com/repos/pydata/pandas/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/pydata/pandas/labels{/name}","releases_url":"https://api.github.com/repos/pydata/pandas/releases{/id}","created_at":"2010-08-24T01:37:33Z","updated_at":"2015-03-01T05:31:06Z","pushed_at":"2015-03-01T14:51:09Z","git_url":"git://github.com/pydata/pandas.git","ssh_url":"git@github.com:pydata/pandas.git","clone_url":"https://github.com/pydata/pandas.git","svn_url":"https://github.com/pydata/pandas","homepage":"http://pandas.pydata.org","size":126120,"stargazers_count":4080,"watchers_count":4080,"language":"Python","has_issues":true,"has_downloads":true,"has_wiki":true,"has_pages":false,"forks_count":1445,"mirror_url":null,"open_issues_count":1349,"forks":1445,"open_issues":1349,"watchers":4080,"default_branch":"master"}},"_links":{"self":{"href":"https://api.github.com/repos/pydata/pandas/pulls/9239"},"html":{"href":"https://github.com/pydata/pandas/pull/9239"},"issue":{"href":"https://api.github.com/repos/pydata/pandas/issues/9239"},"comments":{"href":"https://api.github.com/repos/pydata/pandas/issues/9239/comments"},"review_comments":{"href":"https://api.github.com/repos/pydata/pandas/pulls/9239/comments"},"review_comment":{"href":"https://api.github.com/repos/pydata/pandas/pulls/comments{/number}"},"commits":{"href":"https://api.github.com/repos/pydata/pandas/pulls/9239/commits"},"statuses":{"href":"https://api.github.com/repos/pydata/pandas/statuses/6a5bd899833ee72678e6c61b9e22ba1b24c19878"}},"merged":true,"mergeable":null,"mergeable_state":"unknown","merged_by":{"login":"TomAugspurger","id":1312546,"avatar_url":"https://avatars.githubusercontent.com/u/1312546?v=3","gravatar_id":"","url":"https://api.github.com/users/TomAugspurger","html_url":"https://github.com/TomAugspurger","followers_url":"https://api.github.com/users/TomAugspurger/followers","following_url":"https://api.github.com/users/TomAugspurger/following{/other_user}","gists_url":"https://api.github.com/users/TomAugspurger/gists{/gist_id}","starred_url":"https://api.github.com/users/TomAugspurger/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TomAugspurger/subscriptions","organizations_url":"https://api.github.com/users/TomAugspurger/orgs","repos_url":"https://api.github.com/users/TomAugspurger/repos","events_url":"https://api.github.com/users/TomAugspurger/events{/privacy}","received_events_url":"https://api.github.com/users/TomAugspurger/received_events","type":"User","site_admin":false},"comments":51,"review_comments":49,"commits":1,"additions":255,"deletions":0,"changed_files":6}}