Adding Replace to decoder (to undo the Replace Normalizer for (#1195)

Metaspace split).

bindings/python/tests/bindings/test_decoders.py

@@ -3,7 +3,17 @@ import pickle
 
 import pytest
 
-from tokenizers.decoders import CTC, BPEDecoder, ByteLevel, Decoder, Metaspace, Sequence, WordPiece, ByteFallback
+from tokenizers.decoders import (
+    CTC,
+    BPEDecoder,
+    ByteLevel,
+    Decoder,
+    Metaspace,
+    Sequence,
+    WordPiece,
+    ByteFallback,
+    Replace,
+)
 
 
 class TestByteLevel:
@@ -24,6 +34,18 @@ class TestByteLevel:
         assert isinstance(reloaded, ByteLevel)
 
 
+class TestReplace:
+    def test_instantiate(self):
+        assert Replace("_", " ") is not None
+        assert isinstance(Replace("_", " "), Decoder)
+        assert isinstance(Replace("_", " "), Replace)
+        # assert isinstance(pickle.loads(pickle.dumps(Replace("_", " "))), Replace)
+
+    def test_decoding(self):
+        decoder = Replace("_", " ")
+        assert decoder.decode(["My", "_name", "_is", "_John"]) == "My name is John"
+
+
 class TestWordPiece:
     def test_instantiate(self):
         assert WordPiece() is not None