fixed anomalous backslash in string

03-dict-set/index.py

@@ -8,7 +8,7 @@
 import sys
 import re
 
-WORD_RE = re.compile('\w+')
+WORD_RE = re.compile(r'\w+')
 
 index = {}
 with open(sys.argv[1], encoding='utf-8') as fp:

03-dict-set/index0.py

@@ -8,7 +8,7 @@
 import sys
 import re
 
-WORD_RE = re.compile('\w+')
+WORD_RE = re.compile(r'\w+')
 
 index = {}
 with open(sys.argv[1], encoding='utf-8') as fp:

03-dict-set/index_default.py

@@ -9,7 +9,7 @@ import sys
 import re
 import collections
 
-WORD_RE = re.compile('\w+')
+WORD_RE = re.compile(r'\w+')
 
 index = collections.defaultdict(list)     # <1>
 with open(sys.argv[1], encoding='utf-8') as fp: