This is a sample snippet to ingest data from BigQuery into CARTO by using both Python SDKs

carto-python-bigquery

A snippet to make a query to BigQuery and import the result in CARTO using both Python client libraries:

```
#!/usr/bin/env python

import argparse
import time
import uuid
from tempfile import NamedTemporaryFile

from carto.auth import APIKeyAuthClient
from carto.exceptions import CartoException
from carto.datasets import DatasetManager

from google.cloud import bigquery
from google_auth_oauthlib import flow

USERNAME = "aromeu"
ORGANIZATION = "team"
API_KEY = "WRITE_HERE_YOUR_API_KEY"


USR_BASE_URL = "https://{organization}.carto.com/user/{user}".format(
    organization=ORGANIZATION, user=USERNAME)
auth_client = APIKeyAuthClient(
    api_key=API_KEY, base_url=USR_BASE_URL,
    organization=ORGANIZATION)


def wait_for_job(job):
    while True:
        job.reload()  # Refreshes the state via a GET request.
        if job.state == 'DONE':
            if job.error_result:
                raise RuntimeError(job.errors)
            return
        time.sleep(1)


def run_query(credentials, project, query):
    client = bigquery.Client(project=project, credentials=credentials)
    query_job = client.run_async_query(str(uuid.uuid4()), query)
    query_job.use_legacy_sql = False
    query_job.begin()

    wait_for_job(query_job)

    # Drain the query results by requesting a page at a time.
    query_results = query_job.results()
    page_token = None
    fill_field_names = True

    with NamedTemporaryFile(mode="wb", suffix=".csv") as data:
        while True:
            rows, total_rows, page_token = query_results.fetch_data(
                max_results=1000,
                page_token=page_token)

            if fill_field_names:
                field_names = [field.name for field in query_results.schema]
                if field_names is not None:
                    data.write(",".join(field_names))
                    data.write("\n")
                    fill_field_names = False

            for row in rows:
                row = list(map(str, row))
                data.write(",".join(row) + "\n")

            if not page_token:
                break

        dataset_manager = DatasetManager(auth_client)

        data.flush()
        try:
            with open(data.name, "rb") as archive:
                dataset_manager.create(archive)
        except CartoException as e:
            print("some error ocurred", e)
        except:
            archive.close()
            data.close()


def authenticate_and_query(project, query, launch_browser=True):
    appflow = flow.InstalledAppFlow.from_client_secrets_file(
        'client_secrets.json',
        scopes=['https://www.googleapis.com/auth/bigquery'])

    if launch_browser:
        appflow.run_local_server()
    else:
        appflow.run_console()

    run_query(appflow.credentials, project, query)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument(
        '--launch-browser',
        help='Use a local server flow to authenticate. ',
        action='store_true')
    parser.add_argument('project', help='Project to use for BigQuery billing.')
    parser.add_argument('query', help='BigQuery SQL Query.')

    args = parser.parse_args()

    authenticate_and_query(
        args.project, args.query, launch_browser=args.launch_browser)
```

The `requirements.txt` file:

```
carto==1.0.1
google-cloud-bigquery==0.24.0
google-auth-oauthlib==0.1.0
pytz==2017.2
```

To run the `sample.py` script execute:

```
python sample.py --launch-browser "eternal-ship-170218" "select * from test.test"
```

Where:
- `eternal-ship-170218` is the name of the BigQuery project
- `select * from test.test` is the query
- `--launch-browser` opens a browser window for the OAuth workflow.

In order to enable authentication, you have to put in the same directory a `client_secrets.json` file with the client_id and client_secret (it's a downloadable file from the BigQuery Web UI)