Use None instead of nan when skipping dialects

This fixes #5.
alan-turing-institute · Dec 23, 2019 · b68ae8e · b68ae8e
1 parent 10d7ae4
commit b68ae8e
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Showing 2 changed files with 7 additions and 11 deletions.
diff --git a/clevercsv/consistency.py b/clevercsv/consistency.py
@@ -69,11 +69,7 @@ def consistency_scores(data, dialects, skip=True, logger=print):
     for dialect in sorted(dialects):
         P = pattern_score(data, dialect)
         if P < Qmax and skip:
-            scores[dialect] = {
-                "pattern": P,
-                "type": float("nan"),
-                "Q": float("nan"),
-            }
+            scores[dialect] = {"pattern": P, "type": None, "Q": None}
             logger("%15r:\tP = %15.6f\tskip." % (dialect, P))
             continue
         T = type_score(data, dialect)
@@ -87,10 +83,10 @@ def consistency_scores(data, dialects, skip=True, logger=print):
 
 
 def get_best_set(scores):
-    H = set()
-    Qmax = max((score["Q"] for score in scores.values()))
-    H = set([d for d, score in scores.items() if score["Q"] == Qmax])
-    return H
+    Qscores = [score["Q"] for score in scores.values()]
+    Qscores = filter(lambda q: not q is None, Qscores)
+    Qmax = max(Qscores)
+    return set([d for d, score in scores.items() if score["Q"] == Qmax])
 
 
 def break_ties(data, dialects):

diff --git a/tests/test_unit/test_consistency.py b/tests/test_unit/test_consistency.py
@@ -17,15 +17,15 @@ class ConsistencyTestCase(unittest.TestCase):
     def test_get_best_set_1(self):
         scores = {
             SimpleDialect(",", None, None): {"Q": 1.0},
-            SimpleDialect(";", None, None): {"Q": float("nan")},
+            SimpleDialect(";", None, None): {"Q": None},
             SimpleDialect("|", None, None): {"Q": 2.0},
         }
         H = get_best_set(scores)
         self.assertEqual(H, set([SimpleDialect("|", None, None)]))
 
     def test_get_best_set_2(self):
         scores = {
-            SimpleDialect(";", None, None): {"Q": float("nan")},
+            SimpleDialect(";", None, None): {"Q": None},
             SimpleDialect(",", None, None): {"Q": 1.0},
             SimpleDialect("|", None, None): {"Q": 2.0},
         }