pep up code

src/vigenere/vig.py

@@ -1,17 +1,20 @@
 def encrypt(key, plaintext):
-    out=""
+    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=""
+    out = ""
     for i in range(0, len(cipertext)):
-        pln = ord(cipertext[i])-(ord(key[i%len(key)]) - 0x61)
+        pln = ord(cipertext[i])-(ord(key[i % len(key)]) - 0x61)
         pln = pln + 26 if pln < 0x61 else pln
         out += chr(pln)
     return out
 
+
 if __name__ == "__main__":
     import argparse
     parser = argparse.ArgumentParser()
@@ -22,11 +25,11 @@ if __name__ == "__main__":
     parser.add_argument('--out', metavar='FILE')
     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()])
+    # strip non-alphabetic chars from file and convert to lower case
+    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))