{"task": {"agent_timeout": 1800, "task": "91", "verifier_timeout": 1800, "instruction": "# 91: DS-1000 Task\n\n## Prompt\nProblem:\nI have multi-index df as follows\n\n\n                x  y\nid  date            \nabc 3/1/1994  100  7\n    9/1/1994   90  8\n    3/1/1995   80  9\nWhere dates are stored as str.\n\n\nI want to parse date index. The following statement\n\n\ndf.index.levels[1] = pd.to_datetime(df.index.levels[1])\nreturns error:\n\n\nTypeError: 'FrozenList' does not support mutable operations.\n\n\nA:\n<code>\nimport pandas as pd\n\n\nindex = pd.MultiIndex.from_tuples([('abc', '3/1/1994'), ('abc', '9/1/1994'), ('abc', '3/1/1995')],\n                                 names=('id', 'date'))\ndf = pd.DataFrame({'x': [100, 90, 80], 'y':[7, 8, 9]}, index=index)\n</code>\ndf = ... # put solution in this variable\nBEGIN SOLUTION\n<code>\n\n## What to do\n- Edit `solution/solution.py` so the code passes the DS-1000 tests.\n- Do not access the internet or install new packages; required libraries are preinstalled in the Docker image.\n- Run tests locally via `bash tests/test.sh`.\n\n## Notes\n- Keep the variable names/signatures implied by the prompt/code_context.\n- The evaluator uses the original DS-1000 `code_context` (`test_execution` / `test_string`).\n", "memory": "", "runnable": false, "difficulty": "", "language": "", "cpus": "", "instruction_truncated": false, "category": "", "compose": false, "has_solution": true, "oracle": null, "docker_image": "ds1000:latest", "taskset": "ds1000", "tags": []}, "runs": []}