lazybear

LazyBear

LazyBear is a polars-flavored lazy SQL query builder on top of sqlalchemy. It lets you compose familiar transformations like select, filter, with_columns, join, group_by().agg(...), and sort/order_by against a SQL database, and then materialize results to polars or arrow (or stream them in batches).

The purpose of this library is to provide lazy, polars-like access to a single sql database server, providing multi-site (and multi-server) stable code while pushing most memory-intensive operations to the remote server.

• Quickstart
• API Reference
• Expressions & Namespaces

Installation

pip install lazybear-polars

Quickstart

import sqlalchemy as sa
from lazybear import scan_table, col

# Create a sqlalchemy engine
engine = sa.create_engine('sqlite:///:memory:')

# Scan a table lazily
lf = scan_table('users', engine)

# Chain transformations and materialize
df = (
    lf
    .filter(col('age') >= 30)
    .select('id', 'name')
    .collect()
)
print(df)

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