Improve ImportError traceback for _aligners (#1736)

biopython · Jul 17, 2018 · 8efbf6d · 8efbf6d
1 parent 5dc1f48
commit 8efbf6d
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/Bio/Align/__init__.py b/Bio/Align/__init__.py
@@ -19,7 +19,14 @@
 from Bio.SeqRecord import SeqRecord, _RestrictedDict
 from Bio import Alphabet
 
-from Bio.Align import _aligners
+try:
+    from Bio.Align import _aligners
+except ImportError as e:
+    new_exc = ImportError("{}: you should not import directly from the "
+                          "biopython source directory; please exit the source "
+                          "tree and re-launch your code from there".format(e))
+    new_exc.__cause__ = None
+    raise new_exc
 
 
 class MultipleSeqAlignment(object):