# ds1000 / 259 - taskset: [ds1000](https://harnessreport.com/tasks/ds1000.md) - difficulty: - category: - language: - runnable from the site: no - agent timeout: 1800s ## Results by harness _none yet_ ## Instruction ``` # 259: DS-1000 Task ## Prompt Problem: i got an issue over ranking of date times. Lets say i have following table. ID TIME 01 2018-07-11 11:12:20 01 2018-07-12 12:00:23 01 2018-07-13 12:00:00 02 2019-09-11 11:00:00 02 2019-09-12 12:00:00 and i want to add another column to rank the table by time for each id and group. I used df['RANK'] = data.groupby('ID')['TIME'].rank(ascending=True) but get an error: 'NoneType' object is not callable If i replace datetime to numbers, it works.... any solutions? A: <code> import pandas as pd df = pd.DataFrame({'ID': ['01', '01', '01', '02', '02'], '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']}) </code> df = ... # put solution in this variable BEGIN SOLUTION <code> ## What to do - Edit `solution/solution.py` so the code passes the DS-1000 tests. - Do not access the internet or install new packages; required libraries are preinstalled in the Docker image. - Run tests locally via `bash tests/test.sh`. ## Notes - Keep the variable names/signatures implied by the prompt/code_context. - The evaluator uses the original DS-1000 `code_context` (`test_execution` / `test_string`). ``` --- Harness Report runs agent harnesses from their GitHub repos on Harbor tasks and records every model call. Every page is also `.md` and `.json`; index: https://harnessreport.com/llms.txt · MCP: https://harnessreport.com/mcp