Python 3 renamed hashlib.algorithms to algorithms_guaranteed

IPython/nbformat/sign.py

@@ -27,7 +27,11 b' from .current import read, write'
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
-
+try:
+    # Python 3
+    algorithms = hashlib.algorithms_guaranteed
+except AttributeError:
+    algorithms = hashlib.algorithms
 
 def yield_everything(obj):
     """Yield every item in a container as bytes
@@ -83,7 +87,7 b' class NotebookNotary(LoggingConfigurable):'
             app.initialize()
         return app.profile_dir
     
-    algorithm = Enum(hashlib.algorithms, default_value='sha256', config=True,
+    algorithm = Enum(algorithms, default_value='sha256', config=True,
         help="""The hashing algorithm used to sign notebooks."""
     )
     def _algorithm_changed(self, name, old, new):

IPython/nbformat/tests/test_sign.py

@@ -10,8 +10,6 b''
 # Imports
 #-----------------------------------------------------------------------------
 
-import hashlib
-
 from .. import sign
 from .base import TestsBase
 
@@ -34,7 +32,7 b' class TestNotary(TestsBase):'
     
     def test_algorithms(self):
         last_sig = ''
-        for algo in hashlib.algorithms:
+        for algo in sign.algorithms:
             self.notary.algorithm = algo
             self.notary.sign(self.nb)
             sig = self.nb.metadata.signature