ch03: update from book draft

03-dict-set/index_default.py

@@ -2,7 +2,7 @@
 # http://www.aleax.it/Python/accu04_Relearn_Python_alex.pdf
 # (slide 41) Ex: lines-by-word file index
 
-# BEGIN INDEX_DEFAULT
+# tag::INDEX_DEFAULT[]
 """Build an index mapping word -> list of occurrences"""
 
 import sys
@@ -23,4 +23,4 @@ with open(sys.argv[1], encoding='utf-8') as fp:
 # print in alphabetical order
 for word in sorted(index, key=str.upper):
     print(word, index[word])
-# END INDEX_DEFAULT
+# end::INDEX_DEFAULT[]