python mysql delete statement not working

cursor.execute("DELETE FROM maillist_subscription WHERE id = '"+id+"'")

conn.commit()

You need to commit the change, using the commit() method on the connection object. Most DBAPI interfaces use implicit transactions.

Also, don't use string formatting for SQL query generation! It will open you up to SQL injections:

UNSAFE!!

# What happens if id = "1'; DROP DATABASE somedb" ?
delstatmt = "DELETE FROM `maillist_subscription` WHERE id = '%s'" % (id,)
cursor.execute(delstatmt)
conn.commit()

SAFE!

delstatmt = "DELETE FROM `maillist_subscription` WHERE id = ?"
cursor.execute(delstatmt, (id,))
conn.commit()