Less lines, better, right?

03/c.py

@@ -1,29 +1,21 @@
 import os
 
-f = open(os.path.dirname(__file__)+"/input.txt", "r")
+rucksacks = open(os.path.dirname(__file__) +
+                 "/input.txt", "r").read().splitlines()
 
-tot = 0
-tot2 = 0
+tot, tot2 = 0, 0
 
 priorities = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 
-rucksacks = f.read().splitlines()
-f.close()
-
 for data in rucksacks:
-    left = data[:len(data)//2]
-    right = data[len(data)//2:]
-    common = ''.join(set(left) & set(right))
-    tot += priorities.rfind(common)+1
+    tot += priorities.rfind(''.join(set(data[:len(data)//2])
+                            & set(data[len(data)//2:])))+1
 
 print("First answer: " + str(tot))
 
-start = 0
-end = len(rucksacks)
-step = 3
-for i in range(start, end, step):
-    three = rucksacks[i:i+step]
-    common = ''.join(set(three[0]) & set(three[1]) & set(three[2]))
-    tot2 += priorities.rfind(common)+1
+for i in range(0, len(rucksacks), 3):
+    three = rucksacks[i:i+3]
+    tot2 += priorities.rfind(''.join(set(three[0])
+                                     & set(three[1]) & set(three[2])))+1
 
 print("Second answer: " + str(tot2))