diff -r 5dc6c3673f9d -r 6af6441034f9 day1/exercise/lister.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/day1/exercise/lister.py	Tue Jan 12 19:05:09 2010 +0530
@@ -0,0 +1,13 @@
+s = "1, 3-7, 12, 15, 18-21"
+answer = []
+single = "answer.append( %s )"
+many = "answer.extend(range(%s))"
+COMMA = ','
+MINUS = '-'
+for p in s.split(COMMA):
+    if MINUS not in p:
+        eval( single % (p) )
+    else:
+        p = p.replace( MINUS, COMMA) + '+ 1 '
+        eval( many % (p) )
+print answer