4.10小节完成！

cookbook/c04/p10_iterate_index.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+"""
+Topic: 迭代并跟踪索引
+Desc : 
+"""
+from collections import defaultdict
+
+
+def iterate_index():
+    my_list = ['a', 'b', 'c']
+    for idx, val in enumerate(my_list):
+        print(idx, val)
+    # 索引从1开始
+    for idx, val in enumerate(my_list, 1):
+        print(idx, val)
+
+    # 序列中含有元组的解压
+    data = [ (1, 2), (3, 4), (5, 6), (7, 8) ]
+    for n, (x, y) in enumerate(data):
+        print(n)
+        print(x, y)
+
+
+def parse_data(filename):
+        with open(filename, 'rt') as f:
+            for lineno, line in enumerate(f, 1):
+                fields = line.split()
+                try:
+                    count = int(fields[1])
+                    # ...
+                except ValueError as e:
+                    print('Line {}: Parse error: {}'.format(lineno, e))
+
+
+def word_lines():
+    word_summary = defaultdict(list)
+    with open('myfile.txt', 'r') as f:
+        lines = f.readlines()
+    for idx, line in enumerate(lines):
+        # Create a list of words in current line
+        words = [w.strip().lower() for w in line.split()]
+        for word in words:
+            word_summary[word].append(idx)
+
+if __name__ == '__main__':
+    iterate_index()
+