fix: workaround for non-usual PG_VERSION string

Author: mstyushin

mamonsu/plugins/pgsql/driver/pg8000/core.py

@@ -1416,7 +1416,12 @@ def handle_PARAMETER_STATUS(self, data, ps):
                 pass
 
         elif key == b"server_version":
-            self._server_version = packaging.version.parse(value.decode('ascii'))
+            # LooseVersion() from distutils was able to handle non-relevant strings
+            # in version (like "16.2 (Ubuntu 16.2-1.pgdg20.04+1)")
+            # since distutils became deprecated we need this hack hoping that
+            # postgres package maintainers won't come up with something more exotic
+            string_version = value.decode('ascii').split(' ')[0]
+            self._server_version = packaging.version.parse(string_version)
             if self._server_version < packaging.version.parse('8.2.0'):
                 self._commands_with_count = (
                     b"INSERT", b"DELETE", b"UPDATE", b"MOVE")

mamonsu/plugins/pgsql/driver/pool.py

@@ -124,8 +124,10 @@ def server_version(self, db=None):
         db = self._normalize_db(db)
         if db in self._cache["server_version"]["storage"]:
             return self._cache["server_version"]["storage"][db]
+
+        version_string = self.query("show server_version", db)[0][0]
         result = bytes(
-            self.query("show server_version", db)[0][0], "utf-8")
+            version_string.split(" ")[0], "utf-8")
         self._cache["server_version"]["storage"][db] = "{0}".format(
             result.decode("ascii"))
         return self._cache["server_version"]["storage"][db]