shorten code

src/vigenere/vig.py

@@ -8,9 +8,8 @@ def decrypt(key, cipertext):
     out=""
     for i in range(0, len(cipertext)):
         pln = ord(cipertext[i])-(ord(key[i%len(key)]) - 0x61)
-        if pln < 0x61:
-            pln = pln + 26
-        out = out + chr(pln)
+        pln = pln + 26 if pln < 0x61 else pln
+        out += chr(pln)
     return out
 
 if __name__ == "__main__":
@@ -21,14 +20,10 @@ if __name__ == "__main__":
     command_group.add_argument('--encrypt', metavar='KEY')
     command_group.add_argument('--decrypt', metavar='KEY')
     parser.add_argument('--out', metavar='FILE')
-
     args = parser.parse_args()
-    fd = open(args.FILE, "r")
-    txt_in = fd.read()
-    txt = ""
-    for i in txt_in.lower():
-        if i.isalpha():
-            txt = txt + i
+
+    #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()])
 
     if(args.encrypt != None):
         print(encrypt(args.encrypt, txt))