# ds1000 / 91 - 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 ``` # 91: DS-1000 Task ## Prompt Problem: I have multi-index df as follows x y id date abc 3/1/1994 100 7 9/1/1994 90 8 3/1/1995 80 9 Where dates are stored as str. I want to parse date index. The following statement df.index.levels[1] = pd.to_datetime(df.index.levels[1]) returns error: TypeError: 'FrozenList' does not support mutable operations. A: <code> import pandas as pd index = pd.MultiIndex.from_tuples([('abc', '3/1/1994'), ('abc', '9/1/1994'), ('abc', '3/1/1995')], names=('id', 'date')) df = pd.DataFrame({'x': [100, 90, 80], 'y':[7, 8, 9]}, index=index) </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