PostgresDataTransformer¶

The PostgresDataTransformer class is a Python class that inherits from the BaseDataTransformer class. This class provides methods to retrieve data from a Postgres database using the PostgreSQL Python adapter (psycopg2) and transform it into a pandas dataframe.

Configuration¶

Required Configuration¶

POSTGRES_HOST: Hostname of the Postgres db.
POSTGRES_PORT: Port used by the Postgres db.
POSTGRES_USER: User to use to connect to the Postgres db.
POSTGRES_PASSWORD: Password for POSTGRES_USER.
POSTGRES_DBNAME: Postgres database to use to load/save data.
POSTGRES_SCHEMA: Default Postgres schema to use.

Optional Configuration¶

There is no optional configuration.

Default Configuration¶

There is no default configuration.

Methods¶

transform¶

This method is used to retrieve data from a PostgreSQL database by passing a SQL query to the PostgresDataConnector._load_data method. This method returns a pandas dataframe containing the retrieved data.

transform(sql, *args, **kwargs)

Arguments:

sql (str): A string containing the SQL query to be executed

Returns:

data (pandas dataframe): A pandas dataframe containing the data retrieved from the PostgreSQL database

Usage¶

from lolpop.component import PostgresDataTransformer


config = {
    #insert component config
}

# Define a SQL query to retrieve data from the PostgreSQL database
sql_query = "SELECT * FROM my_table;"

# Create an instance of the PostgresDataTransformer class
pg_transformer = PostgresDataTransformer(conf=config)

# Call the transform method to retrieve the data from the PostgreSQL database
data = pg_transformer.transform(sql_query)

# Print the retrieved data
print(data.head())