Improve the error message for the nbextension.

Closes #1624
10 years ago · 25232daae3
parent e34690dcf4
commit 25232daae3
1 changed files with 2 additions and 1 deletions
--- a/notebook/nbextensions.py
+++ b/notebook/nbextensions.py
@ -1122,7 +1122,8 @@ def _get_nbextension_metadata(module):
    """
    m = import_item(module)
    if not hasattr(m, '_jupyter_nbextension_paths'):
-        raise KeyError('The Python module {} is not a valid nbextension'.format(module))
+        raise KeyError('The Python module {} is not a valid nbextension, '
+                       'it is missing the `_jupyter_nbextension_paths()` method.'.format(module))
    nbexts = m._jupyter_nbextension_paths()
    return m, nbexts