fix incorrect result normalization in setratio and seqratio

HISTORY.md

@@ -1,5 +1,9 @@
 ## Changelog
 
+### v0.20.6
+#### Fixed
+- fix incorrect result normalization in `setratio` and `seqratio`
+
 ### v0.20.5
 #### Fixed
 - fix support for cmake versions below 3.17

docs/conf.py

@@ -22,7 +22,7 @@
 author = 'Max Bachmann'
 
 # The full version, including alpha/beta/rc tags
-release = '0.20.5'
+release = '0.20.6'
 
 # -- General configuration ---------------------------------------------------
 

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="Levenshtein",
-    version="0.20.5",
+    version="0.20.6",
     url="https://github.com/maxbachmann/Levenshtein",
     author="Max Bachmann",
     install_requires=["rapidfuzz >= 2.3.0, < 3.0.0"],

src/Levenshtein/StringMatcher.py

@@ -1,14 +1,15 @@
 from Levenshtein import *
 from warnings import warn
 
+
 class StringMatcher:
     """A SequenceMatcher-like class built on the top of Levenshtein"""
 
     def _reset_cache(self):
         self._ratio = self._distance = None
         self._opcodes = self._editops = self._matching_blocks = None
 
-    def __init__(self, isjunk=None, seq1='', seq2='', autojunk=False):
+    def __init__(self, isjunk=None, seq1="", seq2="", autojunk=False):
         if isjunk:
             warn("isjunk NOT implemented, it will be ignored")
         if autojunk:
@@ -46,8 +47,9 @@ def get_editops(self):
 
     def get_matching_blocks(self):
         if not self._matching_blocks:
-            self._matching_blocks = matching_blocks(self.get_opcodes(),
-                                                    self._str1, self._str2)
+            self._matching_blocks = matching_blocks(
+                self.get_opcodes(), self._str1, self._str2
+            )
         return self._matching_blocks
 
     def ratio(self):

src/Levenshtein/__init__.py

@@ -16,7 +16,7 @@
 
 __author__: str = "Max Bachmann"
 __license__: str = "GPL"
-__version__: str = "0.20.5"
+__version__: str = "0.20.6"
 
 import rapidfuzz.distance.Levenshtein as _Levenshtein
 import rapidfuzz.distance.Indel as _Indel
@@ -37,6 +37,26 @@
     seqratio,
 )
 
+__all__ = [
+    "quickmedian",
+    "median",
+    "median_improve",
+    "setmedian",
+    "setratio",
+    "seqratio",
+    "distance",
+    "ratio",
+    "hamming",
+    "jaro",
+    "jaro_winkler",
+    "editops",
+    "opcodes",
+    "matching_blocks",
+    "apply_edit",
+    "subtract_edit",
+    "inverse",
+]
+
 
 def distance(s1, s2, *, weights=(1, 1, 1), processor=None, score_cutoff=None):
     """
@@ -67,7 +87,7 @@ def distance(s1, s2, *, weights=(1, 1, 1), processor=None, score_cutoff=None):
     -------
     distance : int
         distance between s1 and s2
- 
+
     Raises
     ------
     ValueError

src/Levenshtein/levenshtein_cpp.pyx

@@ -220,7 +220,7 @@ def setratio(strlist1, strlist2, *):
     else:
         dist = lev_set_distance(strings1, strings2)
 
-    return <double>lensum - dist / <double>lensum
+    return (<double>lensum - dist) / <double>lensum
 
 def seqratio(strlist1, strlist2, *):
     """
@@ -235,7 +235,7 @@ def seqratio(strlist1, strlist2, *):
 
     >>> seqratio(['newspaper', 'litter bin', 'tinny', 'antelope'],
     ...          ['caribou', 'sausage', 'gorn', 'woody'])
-    0.21517857142857144
+    0.215178...
     """
 
     strings1 = extract_stringlist(strlist1)
@@ -252,4 +252,4 @@ def seqratio(strlist1, strlist2, *):
     else:
         dist = lev_edit_seq_distance(strings1, strings2)
 
-    return <double>lensum - dist / <double>lensum
+    return (<double>lensum - dist) / <double>lensum

tests/test_seq_ratio.py

@@ -0,0 +1,16 @@
+import Levenshtein
+
+
+def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
+    return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
+
+
+def test_documented():
+    """
+    run tests from documentation
+    """
+    ratio = Levenshtein.seqratio(
+        ["newspaper", "litter bin", "tinny", "antelope"],
+        ["caribou", "sausage", "gorn", "woody"],
+    )
+    assert isclose(ratio, 0.21517857142857144)

tests/test_set_ratio.py

@@ -0,0 +1,16 @@
+import Levenshtein
+
+
+def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
+    return abs(a - b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
+
+
+def test_documented():
+    """
+    run tests from documentation
+    """
+    ratio = Levenshtein.setratio(
+        ["newspaper", "litter bin", "tinny", "antelope"],
+        ["caribou", "sausage", "gorn", "woody"],
+    )
+    assert isclose(ratio, 0.2818452380952381)