# pandas.core.base.DataError: No numeric types to aggregate

- **ID:** `python/pandas-groupby-agg-nonnumeric`
- **Domain:** python
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Groupby mean/sum applied to DataFrame with no numeric columns (all object/string).

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   df.select_dtypes(include='number').groupby(key).mean()
   ```
2. **** (90% success)
   ```
   Convert target column first: df['val'] = pd.to_numeric(df['val'], errors='coerce')
   ```

## Dead Ends

- **** — Returns empty frame when no numeric columns exist (70% fail)
- **** — Fails on non-numeric strings (80% fail)