3 first challenges

mod_26/sol.py

@@ -0,0 +1,19 @@
+#!/usr/bin/python
+
+def rot13(char):
+    c = ord(char)
+    A = ord('A')
+    Z = ord('Z')
+    a = ord('a')
+    z = ord('z')
+    if c >= A and c <= Z:
+        char = chr((c-A+13)%(Z-A+1)+A)
+    elif c >= a and c <= z:
+        char = chr((c-a+13)%(z-a+1)+a)
+    print(char, end='')
+
+with open("flag", "r") as f:
+    flag = f.read()
+    for char in flag:
+        rot13(char)
+