download_look_with_addtl_fields.py

"""
This is a Google Cloud Function, it can be deployed like this:
  gcloud functions deploy download_full_look --env-vars-file .env.yaml --runtime python37 --trigger-http --allow-unauthenticated

You need a requirements.txt in the same directory, to specify the Flask
and Looker SDK versions. You also need a .env.yaml file to contain
environment variable values for the Looker SDK!

Read logs like this:
  gcloud functions logs read download_full_look

"""
import looker_sdk
from looker_sdk import models
from flask import send_file
from tempfile import mktemp


def download_full_look(request):
    sdk = looker_sdk.init31()
    request_args = request.args  # flask.Request object provided by GCP
    if request_args and 'product.name' in request_args:
        name = request_args['product.name']
    else:
        name = 'banana'

    look = sdk.look(1)
    query = look.query
    query.fields.append('product.quantity_on_order')
    filters = {}
    filters['product.name'] = name

    request = create_query_request(query, filters)
    results = sdk.run_inline_query("csv", request, cache=False)

    return(file_for_results(results))


def file_for_results(results):
    fn = mktemp()
    with open(fn, "w") as f:
        f.write(results)
    return send_file(
        fn,
        mimetype="text/csv",
        attachment_filename="results.csv",
        as_attachment=True,
    )


def create_query_request(q: models.Query, filters) -> models.WriteQuery:
    return models.WriteQuery(
        model=q.model,
        view=q.view,
        fields=q.fields,
        pivots=q.pivots,
        fill_fields=q.fill_fields,
        filters=filters,
        sorts=q.sorts,
        limit=q.limit,
        column_limit=q.column_limit,
        total=q.total,
        row_total=q.row_total,
        subtotals=q.subtotals,
        dynamic_fields=q.dynamic_fields,
        query_timezone=q.query_timezone,
    )