From f03e333245147fbaa878cb387203c8974d981dce Mon Sep 17 00:00:00 2001
From: Kyle Conroy <kyleconroy@gmail.com>
Date: Wed, 17 Apr 2024 14:21:30 -0400
Subject: [PATCH] monkeypatch Undefined to show as empty string

---
 lcviz/plugins/metadata_viewer/metadata_viewer.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lcviz/plugins/metadata_viewer/metadata_viewer.py b/lcviz/plugins/metadata_viewer/metadata_viewer.py
index 35a4571f..2aeb9886 100644
--- a/lcviz/plugins/metadata_viewer/metadata_viewer.py
+++ b/lcviz/plugins/metadata_viewer/metadata_viewer.py
@@ -1,9 +1,16 @@
+from astropy.io.fits.card import Undefined
+
 from jdaviz.configs.default.plugins import MetadataViewer
 from jdaviz.core.registries import tray_registry
 
 __all__ = ['MetadataViewer']
 
 
+# monkeypatch astropy.io.fits.card.Undefined to show an empty string
+# instead of '<astropy.io.fits.card.Undefined object at 0x29f5b94d0>'
+Undefined.__str__ = lambda x: ''
+
+
 @tray_registry('lcviz-metadata-viewer', label="Metadata")
 class MetadataViewer(MetadataViewer):
     """