How to tell if Python SQLite database connection or cursor is closed?

Question

Let's say that you have the following code:

import sqlite3

conn = sqlite3.connect('mydb')
cur = conn.cursor()
# some database actions
cur.close()
conn.close()
# more code below

If I try to use the conn or cur objects later on, how could I tell that they are closed? I cannot find a .isclosed() method or anything like it.

Answer 1

You could wrap in a try, except statement:

>>> conn = sqlite3.connect('mydb')
>>> conn.close()
>>> try:
...     one_row = conn.execute("SELECT * FROM my_table LIMIT 1;")
... except sqlite3.ProgrammingError as e:
...     print(e)
Cannot operate on a closed database.

This relies on a shortcut specific to sqlite3.