How to upload a file to Google Cloud Storage on Python 3

Google Cloud Storage is a scalable, fully-managed object storage service provided by Google Cloud Platform (GCP). It allows you to store and retrieve any amount of data securely, making it a reasonable choice for storing various types of files, such as images, videos, backups, and more. With Google Cloud Storage, you can create buckets (containers) to organize and manage your objects (files) and define access control and permissions for different users.

Google Cloud Storage logo
Google Cloud Storage logo

Upload a file to Google Cloud Storage

To upload a file to Google Cloud Storage using Python 3, you'll need to perform the following steps:

Step 1: Create a Google Cloud Platform (GCP) project:

  • Go to the GCP Console

  • Create a new project or use an existing one.

Creating a GCP project
Creating a GCP project

Step 2: Create a new service account:

  • Go back to the Google Cloud Console.

  • In the left navigation menu, go to "IAM & Admin" > "Service accounts".

IAM & Admin
IAM & Admin

  • Click on the "Create Service Account" button.

Creating a service account
Creating a service account

Step 3: Fill in the Service Account details:

  • Enter a name for your service account.

  • You can also add a description (optional).

Service account details
Service account details

Step 4: Assign a role to the service account:

  • Choose the appropriate role for your use case.

  • For GCS access, the "Storage Object Admin" role provides sufficient permissions.

  • If you need more fine-grained control, you can choose the necessary roles accordingly.

Granting the service account access to project
Granting the service account access to project

Granting users access to service account
Granting users access to service account

Step 5: Create and download the JSON key file:

  • Click on the "Create key" button.

Creating a new key for service account
Creating a new key for service account

  • Select the JSON key type.

  • Click on the "Create" button.

  • The JSON file containing your service account credentials will be downloaded to your system. Make sure to keep this file safe and do not share it publicly.

Selecting JSON for service account key
Selecting JSON for service account key

Step 6: Create the Bucket on Google Cloud Storage

  • Navigate to "Google Cloud Storage"

  • On the left-hand side navigation pane, click on "Storage" > "Storage" to access Google Cloud Storage.

  • In the Google Cloud Storage section, click the "Create Bucket" button to begin the process of creating a new bucket.

Creating a new bucket on Cloud Storage
Creating a new bucket on Cloud Storage

  • Provide Bucket details. You will now be taken to the "Create a bucket" page.

  • Click "Create" after providing the required details, click the "Create" button to create the bucket.

Providing details for bucket
Providing details for bucket

Step 7: Install the required Python library:

  • You need to install the Google Cloud Storage library for Python, which provides the necessary functionalities to interact with Google Cloud Storage.

  • Use pip to install it:

pip install google-cloud-storage
Command to install Google Cloud Storage

Step 8: Write Python code to upload a file to Google Cloud Storage:

  • Now, let's write a Python script to upload a file to Google Cloud Storage using the credentials.json file.

from google.cloud import storage
def upload_to_gcs(bucket_name, source_file_path, destination_blob_name, credentials_file):
    # Initialize the Google Cloud Storage client with the credentials
    storage_client = storage.Client.from_service_account_json(credentials_file)
    # Get the target bucket
    bucket = storage_client.bucket(bucket_name)
    # Upload the file to the bucket
    blob = bucket.blob(destination_blob_name)
    blob.upload_from_filename(source_file_path)
    print(f"File {source_file_path} uploaded to gs://{bucket_name}/{destination_blob_name}")
if __name__ == "__main__":
    # Replace the following variables with your specific values
    BUCKET_NAME = "your-bucket-name"
    SOURCE_FILE_PATH = "path/to/your/local/file.txt"
    DESTINATION_BLOB_NAME = "uploaded-file.txt"
    CREDENTIALS_FILE = "path/to/your/credentials.json"
    upload_to_gcs(BUCKET_NAME, SOURCE_FILE_PATH, DESTINATION_BLOB_NAME, CREDENTIALS_FILE)

Note:

  • BUCKET_NAME: Replace your-bucket-name with the name of the bucket you created on Google Cloud Storage. The bucket name must be globally unique across all of Google Cloud Storage, so choose a name that reflects the purpose of the bucket and is not likely to be used by others.

  • SOURCE_FILE_PATH: Replace path/to/your/local/file.txt with the local file path of the file you want to upload to Google Cloud Storage. This should be the absolute or relative path to the file on your local machine that you want to store in the cloud.

  • DESTINATION_BLOB_NAME: Replace uploaded-file.txt with the desired name of the file that will be shown in the bucket after the upload. When you upload the file, it will be stored in the bucket with this specified name.

  • CREDENTIALS_FILE: Replace path/to/your/credentials.json with the file path of the JSON credentials file you downloaded when creating the service account. This JSON file contains the necessary authentication information for the service account, allowing your Python script to interact with Google Cloud Storage securely.

Code explanation

  • Line 1: Here, we import the storage module from the google.cloud package. This module provides the necessary functionality to interact with Google Cloud Storage.

  • Line 3–12: In this section, we define a function named upload_to_gcs that takes four parameters: bucket_name, source_file_path, destination_blob_name, and credentials_file. This function will be responsible for uploading a file to Google Cloud Storage.

  • Line 5: In this part, we create a new storage.Client instance called storage_client by using the from_service_account_json method provided by the Client class. We pass the credentials_file parameter to this method to authenticate the client with the provided service account credentials.
    Line 8: Using the initialized storage_client, we retrieve the specified bucket by calling the bucket method with the bucket_name parameter. This step allows us to interact with the bucket and its objects.

  • Line 10–12: In this section, we create a new blob (object) within the target bucket with the specified destination_blob_name. The blob.upload_from_filename method is used to upload the file from the local source_file_path to the blob in the bucket.

  • Line 14: After the file is successfully uploaded, we print a message to indicate the success and display the URL of the uploaded object in the Google Cloud Storage bucket.

  • Line 16–23: In this part, we have the main code execution block. We define the specific values for BUCKET_NAME, SOURCE_FILE_PATH, DESTINATION_BLOB_NAME, and CREDENTIALS_FILE, and then call the upload_to_gcs function to upload the file to Google Cloud Storage using the provided credentials and configurations.

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