# HappyBase API hello world > [!WARNING] > > **Alpha** > > > This product is > > subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the > [Service Specific > Terms](https://docs.cloud.google.com/terms/service-terms#1). > > Pre-GA products are available "as is" and might have limited support. > > For more information, see the > [launch stage descriptions](https://cloud.google.com/products/#product-launch-stages). This example is a very simple "hello world" application, written in Python, that illustrates how to: - Set up authentication - Connect to a Bigtable instance. - Create a new table. - Write data to the table. - Read the data back. - Delete the table. ## Set up authentication To use the Python samples on this page in a local development environment, install and initialize the gcloud CLI, and then set up Application Default Credentials with your user credentials. 1. [Install](https://docs.cloud.google.com/sdk/docs/install) the Google Cloud CLI. 2. If you're using an external identity provider (IdP), you must first [sign in to the gcloud CLI with your federated identity](https://docs.cloud.google.com/iam/docs/workforce-log-in-gcloud). 3. If you're using a local shell, then create local authentication credentials for your user account: ```bash gcloud auth application-default login ``` You don't need to do this if you're using Cloud Shell. If an authentication error is returned, and you are using an external identity provider (IdP), confirm that you have [signed in to the gcloud CLI with your federated identity](https://docs.cloud.google.com/iam/docs/workforce-log-in-gcloud). For more information, see [Set up authentication for a local development environment](https://docs.cloud.google.com/bigtable/docs/authentication#local-development). ## Running the sample This example uses the [HappyBase package](https://google-cloud-python-happybase.readthedocs.io/en/latest/) of the [Google Cloud Client Library for Python](https://docs.cloud.google.com/python/docs/reference), an implementation of the [HappyBase](http://happybase.readthedocs.io/en/stable/) APIs, to communicate with Bigtable. Use the HappyBase package if you need to move an existing HBase workload to Bigtable. For new applications, see the ["hello world" example that uses the Bigtable package](https://docs.cloud.google.com/bigtable/docs/samples-python-hello). To run this sample program, follow the [instructions for the sample on GitHub](https://github.com/googleapis/python-bigtable/tree/master/samples/hello_happybase). ## Using the HappyBase APIs with Bigtable The sample application connects to Bigtable and demonstrates some simple operations. ### Installing and importing the client library The required Python packages can be installed using [PIP](https://pip.pypa.io/en/stable/) into a [virtualenv environment](https://virtualenv.pypa.io/en/stable/). The sample includes a [requirements file](https://pip.pypa.io/en/stable/user_guide/#requirements-files) defining the needed packages. google-cloud-happybase==0.33.0 six==1.17.0 # See https://github.com/googleapis/google-cloud-python-happybase/issues/128 The modules can then be imported. from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest from google.cloud import happybase ### Connecting to Bigtable Connect to Bigtable by passing a [`bigtable.Client`](https://docs.cloud.google.com/python/docs/reference/bigtable/latest) to a [`happybase.Connection`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-connection.html). # The client must be created with admin=True because it will create a # table. client = bigtable.Client(project=project_id, admin=True) instance = client.instance(instance_id) connection = happybase.Connection(instance=instance) ### Creating a table Use [`Connection.create_table()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-connection.html#google.cloud.happybase.connection.Connection.create_table) to create a table and its column families. > [!NOTE] > **Note:** Columns that are related to one another are typically grouped into a column family. For more information about column families, see the [Bigtable > storage model](https://docs.cloud.google.com/bigtable/docs/overview#storage-model). print("Creating the {} table.".format(table_name)) column_family_name = "cf1" connection.create_table( table_name, {column_family_name: dict()} # Use default options. ) ### Writing rows to a table Get an existing [`Table`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-table.html) with [`Connection.table()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-connection.html#google.cloud.happybase.connection.Connection.table). Use [`Table.put()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-table.html#google.cloud.happybase.table.Table.put) to write a row to the table. print("Writing some greetings to the table.") table = connection.table(table_name) column_name = "{fam}:greeting".format(fam=column_family_name) greetings = [ "Hello World!", "Hello Cloud Bigtable!", "Hello HappyBase!", ] for i, value in enumerate(greetings): # Note: This example uses sequential numeric IDs for simplicity, # but this can result in poor performance in a production # application. Since rows are stored in sorted order by key, # sequential keys can result in poor distribution of operations # across nodes. # # For more information about how to design a Bigtable schema for # the best performance, see the documentation: # # https://cloud.google.com/bigtable/docs/schema-design row_key = "greeting{}".format(i) table.put(row_key, {column_name.encode("utf-8"): value.encode("utf-8")}) ### Reading a row by its key Get a row directly using its key with [`Table.row()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-table.html#google.cloud.happybase.table.Table.row). print("Getting a single greeting by row key.") key = "greeting0".encode("utf-8") row = table.row(key) print("\t{}: {}".format(key, row[column_name.encode("utf-8")])) ### Scanning all table rows Use [`Table.scan()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-table.html#google.cloud.happybase.table.Table.scan) to get a range of rows. print("Scanning for all greetings:") for key, row in table.scan(): print("\t{}: {}".format(key, row[column_name.encode("utf-8")])) ### Deleting a table Delete a table with [`Connection.delete_table()`](https://google-cloud-python-happybase.readthedocs.io/en/latest/happybase-connection.html#google.cloud.happybase.connection.Connection.delete_table). print("Deleting the {} table.".format(table_name)) connection.delete_table(table_name) ## Putting it all together Here is the full example without comments. """Demonstrates how to connect to Cloud Bigtable and run some basic operations. Prerequisites: - Create a Cloud Bigtable cluster. https://cloud.google.com/bigtable/docs/creating-cluster - Set your Google Application Default Credentials. https://developers.google.com/identity/protocols/application-default-credentials """ import argparse from ..utils import wait_for_table from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest from google.cloud import happybase def main(project_id, instance_id, table_name): client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True) instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id) connection = happybase.Connection(instance=instance) try: print("Creating the {} table.".format(table_name)) column_family_name = "cf1" connection.create_table( table_name, {column_family_name: dict()} # Use default options. ) wait_for_table(instance.table(table_name)) print("Writing some greetings to the table.") table = connection.table(table_name) column_name = "{fam}:greeting".format(fam=column_family_name) greetings = [ "Hello World!", "Hello Cloud Bigtable!", "Hello HappyBase!", ] for i, value in enumerate(greetings): row_key = "greeting{}".format(i) table.put(row_key, {column_name.encode("utf-8"): value.encode("utf-8")}) print("Getting a single greeting by row key.") key = "greeting0".encode("utf-8") row = table.row(key) print("\t{}: {}".format(key, row[column_name.encode("utf-8")])) print("Scanning for all greetings:") for key, row in table.scan(): print("\t{}: {}".format(key, row[column_name.encode("utf-8")])) finally: print("Deleting the {} table.".format(table_name)) connection.delete_table(table_name) connection.close() if __name__ == "__main__": parser = argparse.ArgumentParser( description=__doc__, formatter_class=argparse.ArgumentDefaultsHelpFormatter ) parser.add_argument("project_id", help="Your Cloud Platform project ID.") parser.add_argument( "instance_id", help="ID of the Cloud Bigtable instance to connect to." ) parser.add_argument( "--table", help="Table to create and destroy.", default="Hello-Bigtable" ) args = parser.parse_args() main(args.project_id, args.instance_id, args.table)