python-heredoc

Python Heredoc Pattern

Run Python via Bash? Never python -c "..." beyond trivial one-liners. Shell quoting break on f-strings, apostrophes, nested quotes, escape sequences.

Use heredoc syntax instead

uv run python << 'PYTHON_CODE'
import json

data = {"name": "it's working", "value": f"{1 + 2}"}
print(json.dumps(data, indent=2))
PYTHON_CODE

Single quotes round 'PYTHON_CODE' block shell var expansion. $variables and backticks stay literal Python.

With dependencies

uv run --with requests python << 'PYTHON_CODE'
import requests

resp = requests.get("https://api.example.com/data")
print(resp.json())
PYTHON_CODE

Rules

1. Always uv run python (not bare python or python3)
2. Always quote delimiter: << 'PYTHON_CODE' (not << PYTHON_CODE)
3. Closing PYTHON_CODE own line, no leading whitespace
4. Never python -c for code with quotes, f-strings, multiple statements