Updating SQLite using a custom function and a click-powered progress bar

sqlite_progress.py

import click
import sqlite3
import dateparser

count = 0

c = sqlite3.connect("tweets.db")

with click.progressbar(
    length=c.execute("select count(*) from tweets").fetchone()[0],
    label='Updating dates'
) as bar:
    def dateparser_parse(s):
        bar.update(1)
        return dateparser.parse(s).isoformat()
    c.create_function("dateparser_parse", 1, dateparser_parse)
    with c:
        c.execute("""
            update tweets set
                publish_date=dateparser_parse(publish_date);
        """)

I turned this into a tool: https://github.com/simonw/sqlite-transform/