solved first exercise of chapter 6

Author: LambdaDrive

Chapter 6/exercises/Exercise6_11.py

@@ -1,10 +1,17 @@
 def easyCrypto(string):
     letters = 'abcdefghijklmnopqrstuvwxyz'
     cry = {}
-    for i in range(len(letters)-1):
-        if i % 2 != 0:
+    result = ''
+    for i in range(len(letters)-1):   
+        if i % 2 == 0:
             cry[letters[i]] = letters[i+1]
         else:
             cry[letters[i]] = letters[i-1]
-    print(cry)
+        cry['z'] = 'y'
+    for letter in string:
+        if letter.isupper():
+            result += cry[letter.lower()].capitalize()
+        else:
+            result += cry[letter]
+    print(result)
 

Chapter 6/exercises/Exercise6_12.py

@@ -0,0 +1,16 @@
+def letter2number(grade):
+    number = 0
+    if grade[0] == 'A':
+        number = 4
+    if grade[0] == 'B':
+        number = 3
+    if grade[0] == 'C':
+        number = 2
+    if grade[0] == 'D':
+        number = 1
+    if len(grade) > 1:
+        if grade[1] == '+':
+            number += 0.3
+        if grade[1] == '-':
+            number -= 0.3
+    return number