more useful stuff

useful.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 from functools import reduce
-from itertools import permutations, product
+from itertools import permutations, product, combinations
 from collections import defaultdict, deque
 import re, sys
 import math
@@ -12,7 +12,7 @@ def commaline(line):
     return [int(n) for n in line.strip().split(',')]
 
 def headerfooter(f):
-    return text.split('\n\n', maxsplit=1)
+    return f.read().split('\n\n', maxsplit=1)
 
 def pgphs(text):
     return text.split('\n\n')