Fix circular import

openfold/data/errors.py

+# Copyright 2021 AlQuraishi Laboratory
+# Copyright 2021 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""General-purpose errors used throughout the data pipeline"""
+class Error(Exception):
+    """Base class for exceptions."""
+
+
+class MultipleChainsError(Error):
+    """An error indicating that multiple chains were found for a given ID."""

openfold/data/mmcif_parsing.py

@@ -26,7 +26,7 @@ from Bio import PDB
 from Bio.Data import SCOPData
 import numpy as np
 
-from openfold.data.templates import MultipleChainsError
+from openfold.data.errors import MultipleChainsError
 import openfold.np.residue_constants as residue_constants
 
 

openfold/data/templates.py

@@ -26,15 +26,12 @@ from typing import Any, Dict, Mapping, Optional, Sequence, Tuple
 import numpy as np
 
 from openfold.data import parsers, mmcif_parsing
+from openfold.data.errors import Error
 from openfold.data.tools import kalign
 from openfold.data.tools.utils import to_date
 from openfold.np import residue_constants
 
 
-class Error(Exception):
-    """Base class for exceptions."""
-
-
 class NoChainsError(Error):
     """An error indicating that template mmCIF didn't have any chains."""
 
@@ -59,10 +56,6 @@ class CaDistanceError(Error):
     """An error indicating that a CA atom distance exceeds a threshold."""
 
 
-class MultipleChainsError(Error):
-    """An error indicating that multiple chains were found for a given ID."""
-
-
 # Prefilter exceptions.
 class PrefilterError(Exception):
     """A base class for template prefilter exceptions."""