Fixed bug in NANLAST/NANFIRST

The previous code change to make NaN and None ordering consistent made it so that NANLAST did not put NaN last. Oops. It also had made it so that NaN wasn't first for NANFIRST. Oops.
SethMMorton · Feb 27, 2023 · 0e7533d · 0e7533d
1 parent 4352d7b
commit 0e7533d
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Showing 3 changed files with 15 additions and 12 deletions.
diff --git a/natsort/utils.py b/natsort/utils.py
@@ -417,18 +417,21 @@ def parse_number_or_none_factory(
     nan_replace = float("+inf") if alg & ns.NANLAST else float("-inf")
 
     def func(
-        val: Any, _nan_replace: float = nan_replace, _sep: StrOrBytes = sep
+        val: Any,
+        _nan_replace: float = nan_replace,
+        _sep: StrOrBytes = sep,
+        reverse: bool = nan_replace == float("+inf"),
     ) -> BasicTuple:
         """Given a number, place it in a tuple with a leading null string."""
         # Add a trailing string numbers equaling _nan_replace. This will make
         # the ordering between None NaN, and the NaN replacement value...
         # None comes first, then NaN, then the replacement value.
-        if val is None:
-            return _sep, _nan_replace, "1"
-        elif val != val:
+        if val != val:
+            return _sep, _nan_replace, "3" if reverse else "1"
+        elif val is None:
             return _sep, _nan_replace, "2"
         elif val == _nan_replace:
-            return _sep, _nan_replace, "3"
+            return _sep, _nan_replace, "1" if reverse else "3"
         else:
             return _sep, val
 

diff --git a/tests/test_natsorted.py b/tests/test_natsorted.py
@@ -113,8 +113,8 @@ def test_natsorted_handles_mixed_types(
 @pytest.mark.parametrize(
     "alg, expected",
     [
-        (ns.DEFAULT, [None, float("nan"), float("-inf"), 5, "25", 1e40, float("inf")]),
-        (ns.NANLAST, [float("-inf"), 5, "25", 1e40, None, float("nan"), float("inf")]),
+        (ns.DEFAULT, [float("nan"), None, float("-inf"), 5, "25", 1e40, float("inf")]),
+        (ns.NANLAST, [float("-inf"), 5, "25", 1e40, float("inf"), None, float("nan")]),
     ],
 )
 def test_natsorted_consistent_ordering_with_nan_and_friends(

diff --git a/tests/test_parse_number_function.py b/tests/test_parse_number_function.py
@@ -35,17 +35,17 @@ def test_parse_number_factory_makes_function_that_returns_tuple(
         (
             ns.DEFAULT,
             float("nan"),
-            ("", float("-inf"), "2"),
+            ("", float("-inf"), "1"),
         ),  # NaN transformed to -infinity
         (
             ns.NANLAST,
             float("nan"),
-            ("", float("+inf"), "2"),
+            ("", float("+inf"), "3"),
         ),  # NANLAST makes it +infinity
-        (ns.DEFAULT, None, ("", float("-inf"), "1")),  # None transformed to -infinity
-        (ns.NANLAST, None, ("", float("+inf"), "1")),  # NANLAST makes it +infinity
+        (ns.DEFAULT, None, ("", float("-inf"), "2")),  # None transformed to -infinity
+        (ns.NANLAST, None, ("", float("+inf"), "2")),  # NANLAST makes it +infinity
         (ns.DEFAULT, float("-inf"), ("", float("-inf"), "3")),
-        (ns.NANLAST, float("+inf"), ("", float("+inf"), "3")),
+        (ns.NANLAST, float("+inf"), ("", float("+inf"), "1")),
     ],
 )
 def test_parse_number_factory_treats_nan_and_none_special(