Do not fail on importing string tools if missing python-Levenshtein

python-Levenshtein is an optional dependency so trytond.tools.string_ should
not fail on import.

issue8040

trytond/ir/model.py

@@ -24,10 +24,7 @@ from ..pyson import Bool, Eval, PYSONDecoder
 from ..rpc import RPC
 from ..protocols.jsonrpc import JSONDecoder, JSONEncoder
 from ..tools import is_instance_method, cursor_dict, grouped_slice
-try:
-    from ..tools.string import StringMatcher
-except ImportError:
-    from difflib import SequenceMatcher as StringMatcher
+from ..tools.string_ import StringMatcher
 
 __all__ = [
     'Model', 'ModelField', 'ModelAccess', 'ModelFieldAccess', 'ModelButton',

trytond/tools/string_.py

@@ -3,76 +3,82 @@
 
 # Code come from python-Levenshtein
 
-from Levenshtein import opcodes, editops, matching_blocks, ratio, distance
+__all__ = ['StringMatcher', 'StringPartitioned']
+
 from warnings import warn
+try:
+    from Levenshtein import opcodes, editops, matching_blocks, ratio, distance
 
+    class StringMatcher:
+        """A SequenceMatcher-like class built on the top of Levenshtein"""
 
-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 _reset_cache(self):
-        self._ratio = self._distance = None
-        self._opcodes = self._editops = self._matching_blocks = None
+        def __init__(self, isjunk=None, seq1='', seq2=''):
+            if isjunk:
+                warn("isjunk not NOT implemented, it will be ignored")
+            self._str1, self._str2 = seq1, seq2
+            self._reset_cache()
 
-    def __init__(self, isjunk=None, seq1='', seq2=''):
-        if isjunk:
-            warn("isjunk not NOT implemented, it will be ignored")
-        self._str1, self._str2 = seq1, seq2
-        self._reset_cache()
+        def set_seqs(self, seq1, seq2):
+            self._str1, self._str2 = seq1, seq2
+            self._reset_cache()
 
-    def set_seqs(self, seq1, seq2):
-        self._str1, self._str2 = seq1, seq2
-        self._reset_cache()
+        def set_seq1(self, seq1):
+            self._str1 = seq1
+            self._reset_cache()
 
-    def set_seq1(self, seq1):
-        self._str1 = seq1
-        self._reset_cache()
+        def set_seq2(self, seq2):
+            self._str2 = seq2
+            self._reset_cache()
 
-    def set_seq2(self, seq2):
-        self._str2 = seq2
-        self._reset_cache()
+        def get_opcodes(self):
+            if not self._opcodes:
+                if self._editops:
+                    self._opcodes = opcodes(
+                        self._editops, self._str1, self._str2)
+                else:
+                    self._opcodes = opcodes(self._str1, self._str2)
+            return self._opcodes
 
-    def get_opcodes(self):
-        if not self._opcodes:
-            if self._editops:
-                self._opcodes = opcodes(self._editops, self._str1, self._str2)
-            else:
-                self._opcodes = opcodes(self._str1, self._str2)
-        return self._opcodes
+        def get_editops(self):
+            if not self._editops:
+                if self._opcodes:
+                    self._editops = editops(
+                        self._opcodes, self._str1, self._str2)
+                else:
+                    self._editops = editops(self._str1, self._str2)
+            return self._editops
 
-    def get_editops(self):
-        if not self._editops:
-            if self._opcodes:
-                self._editops = editops(self._opcodes, self._str1, self._str2)
-            else:
-                self._editops = editops(self._str1, self._str2)
-        return self._editops
+        def get_matching_blocks(self):
+            if not self._matching_blocks:
+                self._matching_blocks = matching_blocks(self.get_opcodes(),
+                                                        self._str1, self._str2)
+            return self._matching_blocks
 
-    def get_matching_blocks(self):
-        if not self._matching_blocks:
-            self._matching_blocks = matching_blocks(self.get_opcodes(),
-                                                    self._str1, self._str2)
-        return self._matching_blocks
+        def ratio(self):
+            if not self._ratio:
+                self._ratio = ratio(self._str1, self._str2)
+            return self._ratio
 
-    def ratio(self):
-        if not self._ratio:
-            self._ratio = ratio(self._str1, self._str2)
-        return self._ratio
+        def quick_ratio(self):
+            # This is usually quick enough :o)
+            if not self._ratio:
+                self._ratio = ratio(self._str1, self._str2)
+            return self._ratio
 
-    def quick_ratio(self):
-        # This is usually quick enough :o)
-        if not self._ratio:
-            self._ratio = ratio(self._str1, self._str2)
-        return self._ratio
+        def real_quick_ratio(self):
+            len1, len2 = len(self._str1), len(self._str2)
+            return 2.0 * min(len1, len2) / (len1 + len2)
 
-    def real_quick_ratio(self):
-        len1, len2 = len(self._str1), len(self._str2)
-        return 2.0 * min(len1, len2) / (len1 + len2)
-
-    def distance(self):
-        if not self._distance:
-            self._distance = distance(self._str1, self._str2)
-        return self._distance
+        def distance(self):
+            if not self._distance:
+                self._distance = distance(self._str1, self._str2)
+            return self._distance
+except ImportError:
+    from difflib import SequenceMatcher as StringMatcher
 
 
 class StringPartitioned(str):