How to load existing db file to memory in Python sqlite3?

Here is the snippet that I wrote for my flask application:

import sqlite3from io import StringIOdef init_sqlite_db(app):    # Read database to tempfile    con = sqlite3.connect(app.config['SQLITE_DATABASE'])    tempfile = StringIO()    for line in con.iterdump():        tempfile.write('%s\n' % line)    con.close()    tempfile.seek(0)    # Create a database in memory and import from tempfile    app.sqlite = sqlite3.connect(":memory:")    app.sqlite.cursor().executescript(tempfile.read())    app.sqlite.commit()    app.sqlite.row_factory = sqlite3.Row

What about sqlite3.Connection.backup(...)? "This method makes a backup of a SQLite database even while it’s being accessed by other clients, or concurrently by the same connection." Availability: SQLite 3.6.11 or higher. New in version 3.7.

import sqlite3source = sqlite3.connect('existing_db.db')dest = sqlite3.connect(':memory:')source.backup(dest)

sqlite3.Connection.iterdump "[r]eturns an iterator to dump the database in an SQL text format. Useful when saving an in-memory database for later restoration. This function provides the same capabilities as the .dump command in the sqlite3 shell."

Get such an iterator and dump the disk-based database into a memory-based one, and you're ready to compute. When the computation is done, just dump the other way around back to disk.