Merge pull request #310 from jcrist/eq_no_default

Use `==` instead of `is` to check for no_default

toolz/itertoolz.py

@@ -56,7 +56,7 @@ def accumulate(binop, seq, initial=no_default):
         itertools.accumulate :  In standard itertools for Python 3.2+
     """
     seq = iter(seq)
-    result = next(seq) if initial is no_default else initial
+    result = next(seq) if initial == no_default else initial
     yield result
     for elem in seq:
         result = binop(result, elem)
@@ -397,7 +397,7 @@ def get(ind, seq, default=no_default):
         return seq[ind]
     except TypeError:  # `ind` may be a list
         if isinstance(ind, list):
-            if default is no_default:
+            if default == no_default:
                 if len(ind) > 1:
                     return operator.itemgetter(*ind)(seq)
                 elif ind:
@@ -406,12 +406,12 @@ def get(ind, seq, default=no_default):
                     return ()
             else:
                 return tuple(_get(i, seq, default) for i in ind)
-        elif default is not no_default:
+        elif default != no_default:
             return default
         else:
             raise
     except (KeyError, IndexError):  # we know `ind` is not a list
-        if default is no_default:
+        if default == no_default:
             raise
         else:
             return default
@@ -555,7 +555,8 @@ def reduceby(key, binop, seq, init=no_default):
     {True:  set([2, 4]),
      False: set([1, 3])}
     """
-    if init is not no_default and not callable(init):
+    is_no_default = init == no_default
+    if not is_no_default and not callable(init):
         _init = init
         init = lambda: _init
     if not callable(key):
@@ -564,7 +565,7 @@ def reduceby(key, binop, seq, init=no_default):
     for item in seq:
         k = key(item)
         if k not in d:
-            if init is no_default:
+            if is_no_default:
                 d[k] = item
                 continue
             else:
@@ -721,7 +722,7 @@ def pluck(ind, seqs, default=no_default):
         get
         map
     """
-    if default is no_default:
+    if default == no_default:
         get = getter(ind)
         return map(get, seqs)
     elif isinstance(ind, list):
@@ -805,6 +806,7 @@ def join(leftkey, leftseq, rightkey, rightseq,
     d = groupby(leftkey, leftseq)
     seen_keys = set()
 
+    left_default_is_no_default = (left_default == no_default)
     for item in rightseq:
         key = rightkey(item)
         seen_keys.add(key)
@@ -813,10 +815,10 @@ def join(leftkey, leftseq, rightkey, rightseq,
             for match in left_matches:
                 yield (match, item)
         except KeyError:
-            if left_default is not no_default:
+            if not left_default_is_no_default:
                 yield (left_default, item)
 
-    if right_default is not no_default:
+    if right_default != no_default:
         for key, matches in d.items():
             if key not in seen_keys:
                 for match in matches:
@@ -847,7 +849,7 @@ def diff(*seqs, **kwargs):
     if N < 2:
         raise TypeError('Too few sequences given (min 2 required)')
     default = kwargs.get('default', no_default)
-    if default is no_default:
+    if default == no_default:
         iters = zip(*seqs)
     else:
         iters = zip_longest(*seqs, fillvalue=default)

toolz/sandbox/parallel.py

@@ -49,7 +49,7 @@ def fold(binop, seq, default=no_default, map=map, chunksize=128, combine=None):
     chunks = partition_all(chunksize, seq)
 
     # Evaluate sequence in chunks via map
-    if default is no_default:
+    if default == no_default:
         results = map(lambda chunk: reduce(binop, chunk), chunks)
     else:
         results = map(lambda chunk: reduce(binop, chunk, default), chunks)

toolz/sandbox/tests/test_parallel.py

@@ -1,6 +1,10 @@
 from toolz.sandbox.parallel import fold
 from toolz import reduce
 from operator import add
+from pickle import dumps, loads
+
+# is comparison will fail between this and no_default
+no_default2 = loads(dumps('__no__default__'))
 
 
 def test_fold():
@@ -16,3 +20,5 @@ def setadd(s, item):
     assert fold(setadd, [1, 2, 3], set()) == set((1, 2, 3))
     assert (fold(setadd, [1, 2, 3], set(), chunksize=2, combine=set.union)
             == set((1, 2, 3)))
+
+    assert fold(add, range(10), default=no_default2) == fold(add, range(10))

toolz/tests/test_itertoolz.py

@@ -3,6 +3,7 @@
 from toolz.utils import raises
 from functools import partial
 from random import Random
+from pickle import dumps, loads
 from toolz.itertoolz import (remove, groupby, merge_sorted,
                              concat, concatv, interleave, unique,
                              isiterable, getter,
@@ -17,6 +18,10 @@
 from operator import add, mul
 
 
+# is comparison will fail between this and no_default
+no_default2 = loads(dumps('__no__default__'))
+
+
 def identity(x):
     return x
 
@@ -181,6 +186,7 @@ def test_get():
     assert raises(KeyError, lambda: get(10, {'a': 1}))
     assert raises(TypeError, lambda: get({}, [1, 2, 3]))
     assert raises(TypeError, lambda: get([1, 2, 3], 1, None))
+    assert raises(KeyError, lambda: get('foo', {}, default=no_default2))
 
 
 def test_mapcat():
@@ -248,6 +254,8 @@ def test_reduceby():
 
 def test_reduce_by_init():
     assert reduceby(iseven, add, [1, 2, 3, 4]) == {True: 2 + 4, False: 1 + 3}
+    assert reduceby(iseven, add, [1, 2, 3, 4], no_default2) == {True: 2 + 4,
+                                                                False: 1 + 3}
 
 
 def test_reduce_by_callable_default():
@@ -274,6 +282,7 @@ def binop(a, b):
 
     start = object()
     assert list(accumulate(binop, [], start)) == [start]
+    assert list(accumulate(add, [1, 2, 3], no_default2)) == [1, 3, 6]
 
 
 def test_accumulate_works_on_consumable_iterables():
@@ -328,6 +337,9 @@ def test_pluck():
     assert raises(IndexError, lambda: list(pluck(1, [[0]])))
     assert raises(KeyError, lambda: list(pluck('name', [{'id': 1}])))
 
+    assert list(pluck(0, [[0, 1], [2, 3], [4, 5]], no_default2)) == [0, 2, 4]
+    assert raises(IndexError, lambda: list(pluck(1, [[0]], no_default2)))
+
 
 def test_join():
     names = [(1, 'one'), (2, 'two'), (3, 'three')]
@@ -345,6 +357,11 @@ def addpair(pair):
 
     assert result == expected
 
+    result = set(starmap(add, join(first, names, second, fruit,
+                                   left_default=no_default2,
+                                   right_default=no_default2)))
+    assert result == expected
+
 
 def test_getter():
     assert getter(0)('Alice') == 'A'