from collections import Mapping, Set, Sequence
# dual python 2/3 compatability, inspired by the "six" library
string_types = (str, unicode) if str is bytes else (str, bytes)
iteritems = lambda mapping: getattr(mapping, 'iteritems', mapping.items)()
def objwalk(obj, path=(), memo=None):
if memo is None:
memo = set()
iterator = None
if isinstance(obj, Mapping):
iterator = iteritems
elif isinstance(obj, (Sequence, Set)) and not isinstance(obj, string_types):
iterator = enumerate
if iterator:
if id(obj) not in memo:
memo.add(id(obj))
for path_component, value in iterator(obj):
for result in objwalk(value, path + (path_component,), memo):
yield result
memo.remove(id(obj))
else:
yield path, obj
# optional test code from here on
import unittest
class TestObjwalk(unittest.TestCase):
def assertObjwalk(self, object_to_walk, *expected_results):
return self.assertEqual(tuple(sorted(expected_results)), tuple(sorted(objwalk(object_to_walk))))
def test_empty_containers(self):
self.assertObjwalk({})
self.assertObjwalk([])
def test_single_objects(self):
for obj in (None, 42, True, "spam"):
self.assertObjwalk(obj, ((), obj))
def test_plain_containers(self):
self.assertObjwalk([1, True, "spam"], ((0,), 1), ((1,), True), ((2,), "spam"))
self.assertObjwalk({None: 'eggs', 'bacon': 'ham', 'spam': 1},
((None,), 'eggs'), (('spam',), 1), (('bacon',), 'ham'))
# sets are unordered, so we dont test the path, only that no object is missing
self.assertEqual(set(obj for path, obj in objwalk(set((1,2,3)))), set((1,2,3)))
def test_nested_containers(self):
self.assertObjwalk([1, [2, [3, 4]]],
((0,), 1), ((1,0), 2), ((1, 1, 0), 3), ((1, 1, 1), 4))
self.assertObjwalk({1: {2: {3: 'spam'}}},
((1,2,3), 'spam'))
def test_repeating_containers(self):
repeated = (1,2)
self.assertObjwalk([repeated, repeated],
((0, 0), 1), ((0, 1), 2), ((1, 0), 1), ((1, 1), 2))
def test_recursive_containers(self):
recursive = [1, 2]
recursive.append(recursive)
recursive.append(3)
self.assertObjwalk(recursive, ((0,), 1), ((1,), 2), ((3,), 3))
if __name__ == '__main__':
unittest.main()
Diff to Previous Revision
--- revision 1 2011-12-13 09:42:13
+++ revision 2 2011-12-23 22:10:38
@@ -1,25 +1,59 @@
from collections import Mapping, Set, Sequence
-try:
- from six import string_types, iteritems
-except ImportError:
- string_types = (str, unicode) if str is bytes else (str, bytes)
- iteritems = lambda mapping: getattr(mapping, 'iteritems', mapping.items)()
+# dual python 2/3 compatability, inspired by the "six" library
+string_types = (str, unicode) if str is bytes else (str, bytes)
+iteritems = lambda mapping: getattr(mapping, 'iteritems', mapping.items)()
def objwalk(obj, path=(), memo=None):
if memo is None:
memo = set()
+ iterator = None
if isinstance(obj, Mapping):
- if id(obj) not in memo:
- memo.add(id(obj))
- for key, value in iteritems(obj):
- for child in objwalk(value, path + (key,), memo):
- yield child
+ iterator = iteritems
elif isinstance(obj, (Sequence, Set)) and not isinstance(obj, string_types):
+ iterator = enumerate
+ if iterator:
if id(obj) not in memo:
memo.add(id(obj))
- for index, value in enumerate(obj):
- for child in objwalk(value, path + (index,), memo):
- yield child
+ for path_component, value in iterator(obj):
+ for result in objwalk(value, path + (path_component,), memo):
+ yield result
+ memo.remove(id(obj))
else:
yield path, obj
+
+# optional test code from here on
+import unittest
+
+class TestObjwalk(unittest.TestCase):
+ def assertObjwalk(self, object_to_walk, *expected_results):
+ return self.assertEqual(tuple(sorted(expected_results)), tuple(sorted(objwalk(object_to_walk))))
+ def test_empty_containers(self):
+ self.assertObjwalk({})
+ self.assertObjwalk([])
+ def test_single_objects(self):
+ for obj in (None, 42, True, "spam"):
+ self.assertObjwalk(obj, ((), obj))
+ def test_plain_containers(self):
+ self.assertObjwalk([1, True, "spam"], ((0,), 1), ((1,), True), ((2,), "spam"))
+ self.assertObjwalk({None: 'eggs', 'bacon': 'ham', 'spam': 1},
+ ((None,), 'eggs'), (('spam',), 1), (('bacon',), 'ham'))
+ # sets are unordered, so we dont test the path, only that no object is missing
+ self.assertEqual(set(obj for path, obj in objwalk(set((1,2,3)))), set((1,2,3)))
+ def test_nested_containers(self):
+ self.assertObjwalk([1, [2, [3, 4]]],
+ ((0,), 1), ((1,0), 2), ((1, 1, 0), 3), ((1, 1, 1), 4))
+ self.assertObjwalk({1: {2: {3: 'spam'}}},
+ ((1,2,3), 'spam'))
+ def test_repeating_containers(self):
+ repeated = (1,2)
+ self.assertObjwalk([repeated, repeated],
+ ((0, 0), 1), ((0, 1), 2), ((1, 0), 1), ((1, 1), 2))
+ def test_recursive_containers(self):
+ recursive = [1, 2]
+ recursive.append(recursive)
+ recursive.append(3)
+ self.assertObjwalk(recursive, ((0,), 1), ((1,), 2), ((3,), 3))
+
+if __name__ == '__main__':
+ unittest.main()
