Best ChatGPT Prompt for Python Code

You are a senior Python developer with 15 years of experience. Help me with a Python task.

What I'm trying to do: [DESCRIBE THE GOAL IN PLAIN ENGLISH]
Python version: [3.10 / 3.11 / 3.12 / don't know]
Libraries allowed: [list any restrictions, or 'anything on PyPI']
My current code (if any):
```python
[PASTE YOUR CODE]
```
The problem: [what's not working, or what needs to be built]
Expected input format: [what the script receives]
Expected output format: [what the script should produce]
My skill level: [beginner / intermediate / advanced]

Requirements:
- Write clean, Pythonic code (follow PEP 8)
- Use type hints for function signatures
- Add docstrings for functions
- Include error handling for edge cases (empty input, missing files, network errors)
- Show an example of running the code with sample input
- If there's a simpler/more efficient approach, mention it
- Use the standard library when possible — only pull in pip packages when necessary

import csv
from collections import defaultdict
from datetime import datetime

def summarize_by_month(csv_path: str) -> dict[str, float]:
    """Sum transaction amounts by YYYY-MM month."""
    totals: dict[str, float] = defaultdict(float)
    with open(csv_path, newline='') as f:
        reader = csv.DictReader(f)
        for row in reader:
            date = datetime.strptime(row['date'], '%Y-%m-%d')
            key = date.strftime('%Y-%m')
            totals[key] += float(row['amount'])
    return dict(sorted(totals.items()))

if __name__ == '__main__':
    summary = summarize_by_month('transactions.csv')
    for month, total in summary.items():
        print(f"{month}: ${total:,.2f}")