pg-query-python 0.1.3

Python bindings for libpg_query — parse, deparse, and walk PostgreSQL SQL statements

pg-query-python

Python bindings for libpg_query — parse, deparse, and walk PostgreSQL SQL statements.

Ships pre-built wheels with the libpg_query shared library for Linux (x86_64, aarch64) and macOS (x86_64, arm64). No compiler required at install time.

Install

pip install pg-query-python

Usage

Parse SQL to a protobuf AST

from pg_query import parse

tree = parse("SELECT id, name FROM users WHERE active = true")
print(tree)

Deparse an AST back to SQL

from pg_query import parse, deparse

tree = parse("SELECT 1")
sql = deparse(tree)
assert sql == "SELECT 1"

Walk the AST

from pg_query import parse, walk

tree = parse("SELECT id FROM users JOIN orders ON users.id = orders.user_id")
for field_name, node in walk(tree):
    if type(node).DESCRIPTOR.name == "RangeVar":
        print(f"Table: {node.relname}")

Visitor pattern

from pg_query import parse, Visitor

class TableFinder(Visitor):
    def __init__(self):
        self.tables = []

    def visit_RangeVar(self, node):
        self.tables.append(node.relname)

tree = parse("SELECT * FROM users, orders")
finder = TableFinder()
finder.visit(tree)
print(finder.tables)  # ['users', 'orders']

Building from source

If no pre-built wheel is available for your platform, pip will build from source. You'll need git, make, and a C compiler:

pip install pg-query-python --no-binary pg-query-python

To target a specific libpg_query version:

LIBPG_QUERY_TAG=16-latest pip install pg-query-python --no-binary pg-query-python

License

BSD-3-Clause (this package) and BSD-3-Clause + PostgreSQL License (libpg_query).