add string calculator

Author: pockerman

utils/string_sequence_calculator.py

@@ -0,0 +1,59 @@
+import numpy as np
+import textdistance
+import enum
+from src.exceptions import Error
+
+
+class DistanceType(enum.IntEnum):
+    """
+      Defines the status of a `TimeStep` within a sequence.
+      """
+
+    # Denotes the first `TimeStep` in a sequence.
+    COSINE = 0
+
+
+class TextDistanceCalculator(object):
+    """
+    Wrapper class for text distance calculation
+    """
+
+    DISTANCE_TYPES = [DistanceType.COSINE, ]
+
+    @staticmethod
+    def build_calculator(dist_type: DistanceType):
+
+        if dist_type not in TextDistanceCalculator.DISTANCE_TYPES:
+            raise Error("Distance type '{0}' is invalid".format(str(dist_type)))
+
+        if dist_type == DistanceType.COSINE:
+            return textdistance.Cosine()
+
+    def __init__(self, dist_type):
+
+        if dist_type not in TextDistanceCalculator.DISTANCE_TYPES:
+            raise Error("Distance type '{0}' is invalid".format(dist_type))
+
+        self._dist_type = dist_type
+
+    def calculate(self, txt1, txt2, **options):
+
+        # build a calculator
+        calculator = TextDistanceCalculator.build_calculator(dist_type=self._dist_type)
+
+        set_options = getattr(calculator, "set_options", None)
+
+        if set_options is not None:
+            calculator.set_options(**options)
+
+        return calculator.similarity(txt1, txt2)
+
+
+
+
+
+
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+
+
+