Add __str__ functions for Moprheme, MorphemeList (#124)

This way you can tell what the text actually is.

Author: polm

sudachipy/morpheme.py

@@ -19,6 +19,9 @@ def __init__(self, list_, index):
         self.list = list_
         self.index = index
 
+    def __str__(self):
+        return self.surface()
+
     def begin(self):
         return self.list.get_begin(self.index)
 

sudachipy/morphemelist.py

@@ -40,6 +40,9 @@ def __iter__(self):
             yield morpheme.Morpheme(self, index)
         return
 
+    def __str__(self):
+        return ''.join([mm.surface() for mm in self])
+
     def get_begin(self, index):
         return self.input_text.get_original_index(self.path[index].get_begin())