data.py

import csv
import sqlalchemy

# Connect to the database
engine = sqlalchemy.create_engine('postgresql://username:password@localhost:5432/db_name')

# Get a list of all table names
table_names = engine.table_names()

# Open a file for writing
with open('data_dictionary.csv', 'w', newline='') as csvfile:
    # Create a CSV writer
    fieldnames = ['Table Name', 'Column Name', 'Data Type', 'Primary Key', 'Nullable', 'Default Value']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)

    # Write the header row
    writer.writeheader()

    # Get the information for each table
    for table_name in table_names:
        # Get the table's metadata
        metadata = sqlalchemy.MetaData(bind=engine, reflect=True)
        table = sqlalchemy.Table(table_name, metadata, autoload=True)

        # Write the information for each column in the table
        for column in table.columns:
            writer.writerow({'Table Name': table_name, 
                             'Column Name': column.name, 
                             'Data Type': column.type,
                             'Primary Key': column.primary_key,
                             'Nullable': column.nullable,
                             'Default Value': column.server_default
                            })