Add notify

pgnotify/__init__.py

@@ -1,9 +1,27 @@
 from __future__ import absolute_import, division, print_function, unicode_literals
+
 from logx import log
 
-log.set_null_handler()
-from .notify import (  # noqa
+from .notify import (
     await_pg_notifications,
-    get_dbapi_connection,
+    get_dbapi_connection,  # noqa
     start_listening,
 )
+
+log.set_null_handler()
+
+
+def notify(connection, channel, payload):
+    """Send a PostgreSQL notify with a payload
+
+    :param connection: dburi, sqlengine or dbapiconnection
+    :param channel: channel that the notify is sent to
+    :param payload: payload to be sent together with notify
+    """
+    connection = get_dbapi_connection(connection)
+
+    with connection:
+        with connection.cursor() as cursor:
+            cursor.execute("SELECT pg_notify('%s', '%s');", (channel, payload))
+
+    connection.close()

pgnotify/notify.py

@@ -131,7 +131,7 @@ def await_pg_notifications(
                     sig = signal.Signals(signal_int)
                     signal_name = signal.Signals(sig).name
 
-                    log.info(f"woken from slumber by signal: {signal_name}")
+                    log.info("woken from slumber by signal: {}".format(signal_name))
                     yield signal_int
 
                 if cc in r:
@@ -162,5 +162,5 @@ def await_pg_notifications(
             for s in signals_to_handle:
                 if s in original_handlers:
                     signal_name = signal.Signals(s).name
-                    log.debug(f"restoring original handler for: {signal_name}")
+                    log.debug("restoring original handler for: {}".format(signal_name))
                     signal.signal(s, original_handlers[s])

pyproject.toml

@@ -25,3 +25,7 @@ twine = "*"
 wheel = "*"
 isort = "*"
 black = {python=">3.6", version=">=18.9b0", allow_prereleases=true}
+
+[build-system]
+requires = ["poetry"]
+build-backend = "poetry.masonry.api"

tests/test_pgnotify.py

@@ -2,13 +2,14 @@
 
 import os
 import signal
+from unittest import mock
 
 import psycopg2
 from pytest import raises
 from sqlalchemy import create_engine
 from sqlbag import S
 
-from pgnotify import await_pg_notifications
+from pgnotify import await_pg_notifications, notify
 from pgnotify.notify import get_dbapi_connection
 
 SIGNALS_TO_HANDLE = [signal.SIGINT]
@@ -92,3 +93,14 @@ def get_timeout():
             db, "hello", timeout=0.1, yield_on_timeout=True
         ):
             os.kill(os.getpid(), signal.SIGINT)
+
+
+@mock.patch("pgnotify.get_dbapi_connection")
+def test_send_notify(get_dbapi_connection_mock):
+    mock_db = mock.Mock()
+    assert notify(mock_db, "hello", "test") is None
+    get_dbapi_connection_mock.assert_called_once_with(mock_db)
+    connection_mock = get_dbapi_connection_mock.return_value
+    connection_mock.cursor.assert_called_once_with()
+    cursor = connection_mock.cursor.return_value
+    cursor.execute.assert_called_once_with("SELECT pg_notify('hello', 'test');")