From 0649ff8f3cb4605484f1bc1fd13bc55e9207ba0a Mon Sep 17 00:00:00 2001
From: Thomas A Caswell <tcaswell@bnl.gov>
Date: Thu, 14 Feb 2019 16:41:06 -0500
Subject: [PATCH] MNT: do not use 'is not' on literal

py38 raises a SyntaxWarning on this
---
 pyqtgraph/graphicsItems/HistogramLUTItem.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyqtgraph/graphicsItems/HistogramLUTItem.py b/pyqtgraph/graphicsItems/HistogramLUTItem.py
index f85b64dd..7272aef3 100644
--- a/pyqtgraph/graphicsItems/HistogramLUTItem.py
+++ b/pyqtgraph/graphicsItems/HistogramLUTItem.py
@@ -186,7 +186,7 @@ class HistogramLUTItem(GraphicsWidget):
         """Return a lookup table from the color gradient defined by this 
         HistogramLUTItem.
         """
-        if self.levelMode is not 'mono':
+        if self.levelMode != 'mono':
             return None
         if n is None:
             if img.dtype == np.uint8: