pep up code

src/vigenere/vig.py

@@ -1,9 +1,11 @@
 def encrypt(key, plaintext):
     out = ""
     for i in range(0, len(plaintext)):
-        out = out + chr(((ord(key[i%len(key)])+ord(plaintext[i])-(0x61+0x61))%26)+0x61)
+        out += chr(((ord(key[i % len(key)]) +
+                     ord(plaintext[i]) - (2 * 0x61)) % 26)+0x61)
     return out
 
+
 def decrypt(key, cipertext):
     out = ""
     for i in range(0, len(cipertext)):
@@ -12,6 +14,7 @@ def decrypt(key, cipertext):
         out += chr(pln)
     return out
 
+
 if __name__ == "__main__":
     import argparse
     parser = argparse.ArgumentParser()
@@ -23,10 +26,10 @@ if __name__ == "__main__":
     args = parser.parse_args()
 
     # strip non-alphabetic chars from file and convert to lower case
-    txt = ''.join([x for x in open(args.FILE, "r").read().lower() if x.isalpha()])
+    t = ''.join([x for x in open(args.FILE, "r").read().lower() if x.isalpha()])
 
     if(args.encrypt != None):
-        print(encrypt(args.encrypt, txt))
+        print(encrypt(args.encrypt, t))
 
     if(args.decrypt != None):
-        print(decrypt(args.decrypt, txt))
+        print(decrypt(args.decrypt, t))