From 1081e993e59e18829354cba1373696a1635d93e2 Mon Sep 17 00:00:00 2001
From: Patrick Kunzmann <padix.key@gmail.com>
Date: Fri, 31 May 2024 15:34:06 +0200
Subject: [PATCH] Add more descriptive error message

---
 src/biotite/structure/info/atoms.py      | 7 ++++++-
 src/biotite/structure/io/pdbx/convert.py | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/biotite/structure/info/atoms.py b/src/biotite/structure/info/atoms.py
index 3a3290334..6ab063a99 100644
--- a/src/biotite/structure/info/atoms.py
+++ b/src/biotite/structure/info/atoms.py
@@ -72,6 +72,11 @@ def residue(res_name):
     # Avoid circular import
     from ..io.pdbx import get_component
 
-    component = get_component(get_ccd(), res_name=res_name)
+    try:
+        component = get_component(get_ccd(), res_name=res_name)
+    except KeyError:
+        raise KeyError(
+            f"No atom information found for residue '{res_name}' in CCD"
+        )
     component.hetero[:] = res_name not in non_hetero_residues
     return component
diff --git a/src/biotite/structure/io/pdbx/convert.py b/src/biotite/structure/io/pdbx/convert.py
index c347e8abe..fdc44ff1a 100644
--- a/src/biotite/structure/io/pdbx/convert.py
+++ b/src/biotite/structure/io/pdbx/convert.py
@@ -1112,7 +1112,7 @@ def get_component(pdbx_file, data_block=None, use_ideal_coord=True,
         atom_category = _filter(
             atom_category, atom_category["comp_id"].as_array() == res_name
         )
-        if len(atom_category) == 0:
+        if atom_category.row_count == 0:
             raise KeyError(
                 f"No rows with residue name '{res_name}' found in "
                 f"'chem_comp_atom' category"