updated contents from Atlas repo

sequences/sentence.py

@@ -0,0 +1,21 @@
+"""
+Sentence: access words by index
+"""
+
+import re
+import reprlib
+
+RE_WORD = re.compile('\w+')
+
+
+class Sentence:
+
+    def __init__(self, text):
+        self.text = text
+        self.words = RE_WORD.findall(text)  #<1>
+
+    def __getitem__(self, index):
+        return self.words[index]  #<2>
+
+    def __repr__(self):
+        return 'Sentence(%s)' % reprlib.repr(self.text)  #<3>