codex-1up

```bash
# Generate a Python function to calculate factorial using Codex CLI
codex generate --language python --prompt "Write a function to calculate factorial of a number" --output factorial.py
```

This command will:
1. Use the Codex model to generate Python code
2. Create a function that calculates factorial
3. Save the output to factorial.py

The generated code will look something like this:
```python
def factorial(n):
    """Calculate factorial of a number n"""
    if n == 0:
        return 1
    else:
        return n * factorial(n-1)
```

You can then use this function in your Python scripts.