CODEWITHSUNDEEP
pythonazureazure-functions
Ahmad M.
Ahmad M.

Reputation: 524

Files operations on Azure Functions in Python

I have a Azure Function app with Python code running on it. This Python app accesses BigQuery using a JSON file, reads some data and then creates a JSON file from it.

I tried all that makes sense, but Azure ecosystem is strangely convoluted.

from google.cloud import bigquery
from google.oauth2 import service_account
import pandas as pd
import json
import datetime
import logging
import azure.functions as func


def main(mytimer: func.TimerRequest) -> None:
    utc_timestamp = datetime.datetime.utcnow().replace(
        tzinfo=datetime.timezone.utc).isoformat()

    if mytimer.past_due:
        logging.info('The timer is past due!')

    logging.info('Python timer trigger function ran at %s', utc_timestamp)

    # RE01
    key_path = "bigquery-key.json"

    credentials = service_account.Credentials.from_service_account_file(
        key_path,
        scopes=["https://www.googleapis.com/auth/cloud-platform"],
    )

    client = bigquery.Client(
        credentials=credentials,
        project=credentials.project_id,
    )

    project_id = "test-database"

    sql = """
    SELECT *
    FROM test.dummy_table
    """
    # Create a dataframe and save first 10 rows to a list
    df = client.query(sql).to_dataframe()
    top_ten = df["column1"][1:10].to_list()

    with open('top_10.json', 'w') as json_file:
        json.dump(top_ten, json_file)

Can someone tell me where my JSON file is being saved ? I cannot seem to run this function.

Upvotes: 0

Views: 3274

Answers (1)

silent
silent

Reputation: 16138

Anything that you write to local disk inside your Function is lost once the Function execution ends (or latest when your instance gets evicted because of inactivity). If you want to store resulting files, you need to do so on an external storage system. This is exactly what (output) bindings are for. For example to Azure Blob Storage. See here for an example how to use that in python:

https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob#output---python-example

Upvotes: 2

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