extractor.py

#!/usr/bin/env python

import argparse
import contextlib
import csv
import os
import sqlite3

if __name__ == '__main__':
    parser = argparse.ArgumentParser(
            description='''A script that extracts contents from a csv file
            into an sqlite database''')
    parser.add_argument('csv_file',
                        type=argparse.FileType('r'),
                        help='Csv file to be imported')
    args = parser.parse_args()

    db_name = '{}.db'.format(os.path.basename(args.csv_file.name))
    # When used as a context manager, a sqlite connection already commits
    # the transaction, yet it does not close it. That's why it is used
    # combined with contextlib.closing
    with args.csv_file as csv_file,\
        contextlib.closing(sqlite3.connect(db_name)) as conn,\
        conn as connection:

        rows = csv.reader(csv_file, skipinitialspace=True)

        cursor = connection.cursor()
        cursor.execute(""" CREATE TABLE IF NOT EXISTS person (
                                        time timestamp PRIMARY KEY,
                                        name varchar NOT NULL,
                                        age integer
                                    ); """)

        cursor.executemany('insert or ignore into person values (?,?,?)', rows)

        print('{} values inserted'.format(cursor.rowcount))

        entries = cursor.execute("select count(*) from person").fetchone()[0]
        print('Total of {} entries'.format(entries))