From ca2f5b763328c3592a4790cf406a8cac70c936ea 2014-12-15 16:13:59
From: Matthias Bussonnier <bussonniermatthias@gmail.com>
Date: 2014-12-15 16:13:59
Subject: [PATCH] Merge pull request #7204 from jasongrout/widget-warning2

Make the widget warning brief and easy to filter
---

diff --git a/IPython/html/widgets/__init__.py b/IPython/html/widgets/__init__.py
index 9480d95..cb47420 100644
--- a/IPython/html/widgets/__init__.py
+++ b/IPython/html/widgets/__init__.py
@@ -24,6 +24,15 @@ from .widget_selection import RadioButtonsWidget, ToggleButtonsWidget, DropdownW
 from .widget_selectioncontainer import TabWidget, AccordionWidget
 from .widget_string import HTMLWidget, LatexWidget, TextWidget, TextareaWidget
 
-# Warn on import
-from warnings import warn
-warn("IPython widgets are experimental and may change in the future.", FutureWarning, stacklevel=2)
+# We use warn_explicit so we have very brief messages without file or line numbers.
+# The concern is that file or line numbers will confuse the interactive user.
+# To ignore this warning, do:
+#
+#     from warnings import filterwarnings
+#     filterwarnings('ignore', module='IPython.html.widgets')
+
+from warnings import warn_explicit
+__warningregistry__ = {}
+warn_explicit("IPython widgets are experimental and may change in the future.",
+              FutureWarning, '', 0, module = 'IPython.html.widgets',
+              registry = __warningregistry__, module_globals = globals)