Minor edits to the target_session_attrs patch.

Author: elprans

Diff for: asyncpg/connect_utils.py

@@ -611,21 +611,19 @@ def _parse_connect_dsn_and_args(*, dsn, host, port, user,
             'a Dict[str, str]')
 
     if target_session_attrs is None:
-
         target_session_attrs = os.getenv(
             "PGTARGETSESSIONATTRS", SessionAttribute.any
         )
     try:
-
         target_session_attrs = SessionAttribute(target_session_attrs)
-    except ValueError as exc:
+    except ValueError:
         raise exceptions.InterfaceError(
             "target_session_attrs is expected to be one of "
             "{!r}"
             ", got {!r}".format(
                 SessionAttribute.__members__.values, target_session_attrs
             )
-        ) from exc
+        ) from None
 
     params = _ConnectionParameters(
         user=user, password=password, database=database, ssl=ssl,

Diff for: asyncpg/connection.py

@@ -2008,18 +2008,18 @@ async def connect(dsn=None, *,
         If specified, check that the host has the correct attribute.
         Can be one of:
 
-        "any": the first successfully connected host
-        "primary": the host must NOT be in hot standby mode
-        "standby": the host must be in hot standby mode
-        "read-write": the host must allow writes
-        "read-only": the host most NOT allow writes
-        "prefer-standby": first try to find a standby host, but if
-        none of the listed hosts is a standby server,
-        return any of them.
-
-        If not specified will try to use PGTARGETSESSIONATTRS
-        from the environment.
-        Defaults to "any" if no value is set.
+        - ``"any"`` - the first successfully connected host
+        - ``"primary"`` - the host must NOT be in hot standby mode
+        - ``"standby"`` - the host must be in hot standby mode
+        - ``"read-write"`` - the host must allow writes
+        - ``"read-only"`` - the host most NOT allow writes
+        - ``"prefer-standby"`` - first try to find a standby host, but if
+          none of the listed hosts is a standby server,
+          return any of them.
+
+        If not specified, the value parsed from the *dsn* argument is used,
+        or the value of the ``PGTARGETSESSIONATTRS`` environment variable,
+        or ``"any"`` if neither is specified.
 
     :return: A :class:`~asyncpg.connection.Connection` instance.
 
@@ -2086,6 +2086,9 @@ async def connect(dsn=None, *,
     .. versionchanged:: 0.26.0
        Added the *direct_tls* parameter.
 
+    .. versionchanged:: 0.28.0
+       Added the *target_session_attrs* parameter.
+
     .. _SSLContext: https://docs.python.org/3/library/ssl.html#ssl.SSLContext
     .. _create_default_context:
         https://docs.python.org/3/library/ssl.html#ssl.create_default_context