A faster identity function from cytoolz

OpenNTI · Sep 20, 2017 · 34011e4 · 34011e4
1 parent 105a06d
commit 34011e4
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Showing 2 changed files with 15 additions and 3 deletions.
diff --git a/setup.py b/setup.py
@@ -80,12 +80,19 @@ def _read(fname):
         'zope.security',
     ],
     extras_require={
+        ':platform_python_implementation=="CPython"': [
+            'cytoolz >= 0.8.2',
+        ],
+        ':platform_python_implementation=="PyPy"': [
+            'toolz',
+        ],
         'test': TESTS_REQUIRE,
         'docs': [
             'Sphinx',
             'repoze.sphinx.autointerface',
             'sphinx_rtd_theme',
-        ]
+        ],
+
     },
     entry_points=entry_points,
 )
diff --git a/src/nti/externalization/externalization.py b/src/nti/externalization/externalization.py
@@ -20,6 +20,11 @@
 import persistent
 import six
 
+try:
+    from cytoolz import identity
+except ImportError: # PyPy pragma: no cover
+    from toolz import identity
+
 from zope import component
 from zope import deprecation
 from zope import interface
@@ -400,9 +405,9 @@ def datetime_to_epoch(dt):
 
 
 def choose_field(result, self, ext_name,
-                 converter=lambda _: _,
+                 converter=identity,
                  fields=(),
-                 sup_iface=None, sup_fields=(), sup_converter=lambda _: _):
+                 sup_iface=None, sup_fields=(), sup_converter=identity):
 
     for x in fields:
         try: