Data Cleaning Script

Write a {{language}} script to clean this dataset. Here is the structure:

Columns: {{column_definitions}}
Row count: approximately {{row_count}}
Known issues:
{{data_issues}}

For each issue, implement a cleaning step that:
1. Logs how many rows are affected before the fix
2. Applies the transformation
3. Validates the result

After cleaning, generate a summary report showing:
- Rows before/after
- Columns modified
- Values imputed or removed
- Any rows flagged for manual review

Use {{library}} for data manipulation. Add error handling so the script does not fail silently on unexpected values.