all Python 3sqlite3function

sqlite3.enable_callback_tracebacks()

utility functions

Turns on traceback printing to stderr when your function called from SQL (create_function, an aggregate, a converter) fails. Off by default.

Syntax

sqlite3.enable_callback_tracebacks(flag, /)

Without it, an error inside a user-defined function turns into a faceless OperationalError 'user-defined function raised exception', and the real cause — ZeroDivisionError, KeyError — is lost. After enable_callback_tracebacks(True) the original exception goes to sys.unraisablehook and is printed to stderr, yet the query still fails with the same OperationalError. The flag is global for the whole process.

Examples

# Python 3.11+
import sqlite3
import sys
conn = sqlite3.connect(':memory:')
conn.create_function('half', 1, lambda x: x / 0)
try:
    conn.execute('SELECT half(4)')
except sqlite3.OperationalError as e:
    print(e)  # → user-defined function raised exception
sqlite3.enable_callback_tracebacks(True)
seen = []
sys.unraisablehook = lambda u: seen.append(type(u.exc_value).__name__)
try:
    conn.execute('SELECT half(4)')
except sqlite3.OperationalError:
    print(seen)  # → ['ZeroDivisionError'] — настоящая причина
conn.close()

See also

Common errors

Open in the full glossarydocs.python.orgReport an inaccuracy