Skip to main content

Safety and Limitations

py-sql-cleaner is conservative by default. It skips unsafe blocks instead of rewriting them.

note

Skipped blocks are left unchanged. Preserving runtime behavior is more important than formatting every SQL-looking string.

Unsafe Blocks​

f-strings are skipped by default:

query = f"""
SELECT *
FROM users
WHERE user_id = {user_id}
"""

Jinja-like templates are also skipped during formatting:

query = """
SELECT *
FROM users
WHERE ds = '{{ ds }}'
"""

Reasons:

  • f-strings may contain Python expressions
  • Jinja-like templates may be used by Airflow, dbt, or other tools
  • rewriting these strings incorrectly could change runtime behavior

What py-sql-cleaner Does Not Do​

py-sql-cleaner does not:

  • connect to databases
  • execute SQL
  • validate SQL against a database
  • inspect schemas
  • provide autocomplete
  • guarantee full database compatibility
  • fully support f-strings
  • fully support Jinja templates
  • format every possible SQL string