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 always skipped by format and extract:

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

Jinja-like templates are also always skipped by format and extract:

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

Runtime placeholders are also always skipped by format and extract:

query = """
SELECT *
FROM users
WHERE user_id = :user_id
"""

query = """
SELECT *
FROM users
WHERE user_id = %s
"""

Reasons:

f-strings may contain Python expressions
Jinja-like templates may be used by Airflow, dbt, or other tools
placeholders such as :user_id, %s, and %(user_id)s are filled by a database driver or query builder
these strings are completed at runtime, after Python, a template engine, a database driver, or a query builder fills in values
rewriting these strings incorrectly could change runtime behavior

py-sql-cleaner does not: