diff --git a/src/sectubs/exercises.py b/src/sectubs/exercises.py
index a72c6c1..cfd2b21 100644
--- a/src/sectubs/exercises.py
+++ b/src/sectubs/exercises.py
@@ -1,5 +1,6 @@
 import datetime
 
+
 class Exercise00:
     STUDENT_NAME = "Eggert Jung"
 
@@ -38,40 +39,27 @@ class Exercise00:
     def __str__(self):
         return b64_enc(self.__txt)
 
-def b64_enc_map(index):
-    if(index >= 0  and index < 26):
-        return chr(index + 0x41) # A-Z
-    elif(index >= 26 and index < 52):
-        return chr(index + 0x61 - 26) # a-z
-    elif(index >= 52 and index < 62):
-        return chr(index + 0x30 - 52) # 0-9
-    elif(index == 62):
-        return '+'
-    elif(index == 63):
-        return '/'
-    else:
-        return '='
 
 def b64_enc(str):
     res = ""
-
+    b64_map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
     for c in [(str[i:i+3]) for i in range(0, len(str), 3)]:
         c = bytes(c, 'utf-8')
-        bits = [-1,-1,-1,-1]
+        bits = [64, 64, 64, 64]
         try:
-            bits[0] = (c[0] & 0xFC)>>2
+            bits[0] = (c[0] & 0xFC) >> 2
 
-            bits[1] = ((c[0] & 0x03)<<4)
-            bits[1] = bits[1] + ((c[1] & 0xF0)>>4)
+            bits[1] = ((c[0] & 0x03) << 4)
+            bits[1] = bits[1] + ((c[1] & 0xF0) >> 4)
 
-            bits[2] = ((c[1] & 0x0F)<<2)
-            bits[2] = bits[2] + ((c[2] & 0xC0)>>6)
+            bits[2] = ((c[1] & 0x0F) << 2)
+            bits[2] = bits[2] + ((c[2] & 0xC0) >> 6)
 
             bits[3] = (c[2] & 0x3F)
         except IndexError:
             pass
         for i in range(4):
-            res = res + b64_enc_map(bits[i])
+            res = res + b64_map[bits[i]]
     return res
 
 
@@ -79,11 +67,15 @@ if __name__ == "__main__":
     import argparse
     parser = argparse.ArgumentParser()
     parser.add_argument('FILE', help="The input positional parameter.")
-    parser.add_argument('-b', '--bool', action='store_true', help="An optional boolean flag (Default: False).")
-    parser.add_argument('-f', '--float', default=0.0, type=float, help="An optional parameter of type float (Default: 0.0).")
-    parser.add_argument('-i', '--int', default=0, type=int, help="An optional parameter of type int (Default: 0).")
+    parser.add_argument('-b', '--bool', action='store_true',
+                        help="An optional boolean flag (Default: False).")
+    parser.add_argument('-f', '--float', default=0.0, type=float,
+                        help="An optional parameter of type float (Default: 0.0).")
+    parser.add_argument('-i', '--int', default=0, type=int,
+                        help="An optional parameter of type int (Default: 0).")
 
     args = parser.parse_args()
-    print("input: {FILE}\n--bool {bool}\n--float {float}\n--int {int}".format(**args.__dict__))
+    print(
+        "input: {FILE}\n--bool {bool}\n--float {float}\n--int {int}".format(**args.__dict__))
 
     exit(42)