Google BigQuery

To read or write from GBQ, additional dependencies are needed:

Python

$ pip install google-cloud-bigquery

Read

We can load a query into a DataFrame like this:

Python

from_arrow · Available on feature fsspec · Available on feature pyarrow

import polars as pl
from google.cloud import bigquery

client = bigquery.Client()

# Perform a query.
QUERY = (
    'SELECT name FROM `bigquery-public-data.usa_names.usa_1910_2013` '
    'WHERE state = "TX" '
    'LIMIT 100')
query_job = client.query(QUERY)  # API request
rows = query_job.result()  # Waits for query to finish

df = pl.from_arrow(rows.to_arrow())

Write

Python

from google.cloud import bigquery

client = bigquery.Client()

# Write DataFrame to stream as parquet file; does not hit disk
with io.BytesIO() as stream:
    df.write_parquet(stream)
    stream.seek(0)
    job = client.load_table_from_file(
        stream,
        destination='tablename',
        project='projectname',
        job_config=bigquery.LoadJobConfig(
            source_format=bigquery.SourceFormat.PARQUET,
        ),
    )
job.result()  # Waits for the job to complete