Convert CSV or Database data to JSON

to_json.py

import cx_Oracle as oracle
import argparse, csv, json, os, os.path

QUERY = 'SELECT * FROM ESDV.V_ETD_EMPE'
ROW_KEY = 'ETD Record Key'

def from_database(credentials):
    data = {}
    with oracle.connect(credentials) as conn:
        cursor = conn.cursor()
        for row in cursor.execute(QUERY):
            ppid = row[0]
            data.setdefault(ppid, {})
            # The cursor.description includes a bunch of info for each column; first is the name.
            column_names = [x for x in map(lambda l: l[0], cursor.description)]
            for column_name, row_value in zip(column_names, row):
                data[ppid].setdefault(column_name, []).append(row_value)
    return data

def from_csv(csv_path, csv_encoding='utf-8'):
    data = {}
    csv_path = os.path.abspath(csv_path)
    with open(csv_path, encoding=csv_encoding) as csv_file:
        csv_reader = csv.DictReader(csv_file)
        for row in csv_reader:
            data[row[ROW_KEY]] = row
    return data

def export(output_path, data):
    output_path = os.path.abspath(output_path)
    with open(output_path, 'w') as output_file:
        json.dump(data, output_file, ensure_ascii=False, indent=2)

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Convert data to json.')
    parser.add_argument('output', help='Path to the output file')
    parser.add_argument('--csv-path', '-c', help='Path to the CSV file to convert')
    parser.add_argument('--database', '-d', help='Pull data from a database.', action='store_true')
    args = parser.parse_args()

    if args.database:
        export(args.output, from_database(os.environ['ETD_ESD_CONNECTION']))
    elif args.csv_path:
        export(args.output, from_csv(args.csv_path))
    else:
        print('Please specify one of the available data sources via arguments')
        parser.print_help()