Added zen.txt file for chapter 3

Author: pacificpatel165

03-dict-set/index0.py

@@ -11,7 +11,7 @@
 WORD_RE = re.compile('\w+')
 
 index = {}
-with open(sys.argv[1], encoding='utf-8') as fp:
+with open('zen.txt', encoding='utf-8') as fp:
     for line_no, line in enumerate(fp, 1):
         for match in WORD_RE.finditer(line):
             word = match.group()

03-dict-set/index_default.py

@@ -12,7 +12,7 @@
 WORD_RE = re.compile('\w+')
 
 index = collections.defaultdict(list)     # <1>
-with open(sys.argv[1], encoding='utf-8') as fp:
+with open('zen.txt', encoding='utf-8') as fp:
     for line_no, line in enumerate(fp, 1):
         for match in WORD_RE.finditer(line):
             word = match.group()

03-dict-set/zen.txt

@@ -0,0 +1,21 @@
+The Zen of Python, by Tim Peters
+
+Beautiful is better than ugly.
+Explicit is better than implicit.
+Simple is better than complex.
+Complex is better than complicated.
+Flat is better than nested.
+Sparse is better than dense.
+Readability counts.
+Special cases aren't special enough to break the rules.
+Although practicality beats purity.
+Errors should never pass silently.
+Unless explicitly silenced.
+In the face of ambiguity, refuse the temptation to guess.
+There should be one-- and preferably only one --obvious way to do it.
+Although that way may not be obvious at first unless you're Dutch.
+Now is better than never.
+Although never is often better than *right* now.
+If the implementation is hard to explain, it's a bad idea.
+If the implementation is easy to explain, it may be a good idea.
+Namespaces are one honking great idea -- let's do more of those!