{"kind":"task","effective_mode":"full","benchmark":{"kind":"benchmark","effective_mode":"full","slug":"ds-1000","formal_name":"DS-1000","introduction":"DS-1000 builds 1,000 data-science problems from real StackOverflow questions across seven libraries including NumPy, Pandas and Matplotlib. The problems are perturbed so that recalling the original answer does not solve them.","introduction_ja":"","introduction_en":"","category":"Category not supplied","task_count":null,"acquisition_status":"Acquisition status not supplied","official_url":"https://ds1000-code-gen.github.io/","indexing_mode":"index","profile":{"resources":[],"task_format":"","scoring":"","metric":"","size":"","answer_access":"","license":"","citation":"","maintainer":"","released":"","why_hard":"","related":[],"history":"","construction":"","limitations":"","saturation":"","scores":[]}},"task_id":"d1ccf944-273e-5dbd-ba1f-9cb23fd8033a","task_key":"default--test--259","task_revision_id":"1","upstream_id":"259","short_description":"i got an issue over ranking of date times. Lets say i have following table.","config":"default","split":"test","body":"{\"library\":\"Pandas\",\"prompt\":\"Problem:\\ni got an issue over ranking of date times. Lets say i have following table.\\nID    TIME\\n01    2018-07-11 11:12:20\\n01    2018-07-12 12:00:23\\n01    2018-07-13 12:00:00\\n02    2019-09-11 11:00:00\\n02    2019-09-12 12:00:00\\n\\n\\nand i want to add another column to rank the table by time for each id and group. I used \\ndf['RANK'] = data.groupby('ID')['TIME'].rank(ascending=True)\\n\\n\\nbut get an error:\\n'NoneType' object is not callable\\n\\n\\nIf i replace datetime to numbers, it works.... any solutions?\\n\\n\\nA:\\n<code>\\nimport pandas as pd\\n\\n\\ndf = pd.DataFrame({'ID': ['01', '01', '01', '02', '02'],\\n                   'TIME': ['2018-07-11 11:12:20', '2018-07-12 12:00:23', '2018-07-13 12:00:00', '2019-09-11 11:00:00', '2019-09-12 12:00:00']})\\n</code>\\ndf = ... # put solution in this variable\\nBEGIN SOLUTION\\n<code>\\n\"}","display_format":"code","language":"","answer_status":"published","assets":[],"source_url":"https://ds1000-code-gen.github.io/","history":"initial import","indexing_mode":"index","subproblems":[],"grids":[]}