Making it Pythonic: create a sqlite3 database if it doesn't exist?

Question

I wrote a Python script which initializes an empty database if it doesn't exist.

import os

if not os.path.exists('Database'):
    os.makedirs('Database')
    os.system('sqlite3 Database/testDB.db ";"')

# rest of the script...

Can I do this in a more Pythonic fashion, with a try-except, or is this kind of code acceptable?

Answer 1

I think you can do it like this:

import sqlite3
conn = sqlite3.connect('Database/testDB.db')

This should connect to your database and create it in case that it doesn't exist. I'm not sure this is the most pythonic way, but it does use the sqlite3 module instead of the sqlite3 command.

Answer 2

Making it Pythonic: create a sqlite3 database if it doesn't exist?

The most Pythonic way to do this is to use the context manager:

import sqlite3

# if we error, we rollback automatically, else commit!
with sqlite3.connect('/Temp/testDB.db') as conn:
    cursor = conn.cursor()
    cursor.execute('SELECT SQLITE_VERSION()')
    data = cursor.fetchone()
    print('SQLite version:', data)

In a python shell this echoes for me:

<sqlite3.Cursor object at 0x0CCAD4D0>
SQLite version: (u'3.5.9',)

To ensure you have a tempfile path that works across platforms, use tempfile.gettempdir:

import tempfile
with sqlite3.connect(tempfile.gettempdir() + '/testDB.db') as conn:
    ...