updated contents from Atlas repo

iterables/sentence_iter.py

@@ -0,0 +1,65 @@
+"""
+Sentence: iterate over words using the Iterator Pattern, take #1
+
+WARNING: the Iterator Pattern is much simpler in idiomatic Python;
+see: sentence_gen*.py.
+"""
+
+# BEGIN SENTENCE_ITER
+import re
+import reprlib
+
+RE_WORD = re.compile('\w+')
+
+
+class Sentence:
+
+    def __init__(self, text):
+        self.text = text
+        self.words = RE_WORD.findall(text)
+
+    def __repr__(self):
+        return 'Sentence(%s)' % reprlib.repr(self.text)
+
+    def __iter__(self):  # <1>
+        return SentenceIter(self.words)  # <2>
+
+
+class SentenceIter:
+
+    def __init__(self, words):
+        self.words = words  # <3>
+        self.index = 0  # <4>
+
+    def __next__(self):
+        try:
+            word = self.words[self.index]  # <5>
+        except IndexError:
+            raise StopIteration()  # <6>
+        self.index += 1  # <7>
+        return word  # <8>
+
+    def __iter__(self):  # <9>
+        return self
+# END SENTENCE_ITER
+
+def main():
+    import sys
+    import warnings
+    try:
+        filename = sys.argv[1]
+        word_number = int(sys.argv[2])
+    except (IndexError, ValueError):
+        print('Usage: %s <file-name> <word-number>' % sys.argv[0])
+        sys.exit(1)
+    with open(filename, 'rt', encoding='utf-8') as text_file:
+        s = Sentence(text_file.read())
+    for n, word in enumerate(s, 1):
+        if n == word_number:
+            print(word)
+            break
+    else:
+        warnings.warn('last word is #%d, "%s"' % (n, word))
+
+if __name__ == '__main__':
+    main()