Merge pull request 'Aufgabe who likes it, Codewars Uebung kyu6' (#4) from Woche4 into master

Reviewed-on: #4

src/Woche2/aufgabe2.py

@@ -0,0 +1,41 @@
+def key_string(key, text):
+    keystring = key
+    while len(keystring) <= len(text):
+        keystring += key
+    return keystring[: len(text)]
+
+
+class VigenereCipher(object):
+    def __init__(self, key, alphabet):
+        self.alphabet = alphabet
+        self.key = key
+        self.keymap = []
+        for i in range(len(alphabet)):
+            self.keymap.append(alphabet)
+            alphabet = alphabet[1:] + alphabet[0]
+
+    def encode(self, text):
+        keystring = key_string(self.key, text)
+        encode_string = ""
+
+        for index, i in enumerate(text):
+            index_alpha = self.alphabet.find(i)
+            if index_alpha == -1:
+                encode_string += i
+            else:
+                index_key = self.alphabet.find(keystring[index])
+                encode_string += self.keymap[index_key][index_alpha]
+        return encode_string
+
+    def decode(self, text):
+        keystring = key_string(self.key, text)
+        decode_string = ""
+
+        for index, i in enumerate(text):
+            if self.alphabet.find(i) == -1:
+                decode_string += i
+            else:
+                index_key = self.alphabet.find(keystring[index])
+                index_alpha = self.keymap[index_key].find(i)
+                decode_string += self.alphabet[index_alpha]
+        return decode_string

src/Woche3/menu.py

@@ -0,0 +1,15 @@
+class Menu:
+    def __init__(self, menu):
+        self.menu = menu
+        self.selected = 0
+
+    def to_the_right(self):
+        self.selected = (self.selected + 1) % len(self.menu)
+
+    def to_the_left(self):
+        self.selected = (self.selected - 1) % len(self.menu)
+
+    def display(self):
+        display_array = self.menu[:]
+        display_array[self.selected] = [display_array[self.selected]]
+        return str(display_array)

src/Woche4/Aufgabe_who_likes_it.py

@@ -0,0 +1,13 @@
+def likes(names):
+    length = len(names)
+    for i in range(4):
+        names.append("")
+
+    text = [
+        "no one likes this",
+        names[0] + " likes this",
+        names[0] + " and " + names[1] + " like this",
+        names[0] + ", " + names[1] + " and " + names[2] + " like this",
+        names[0] + ", " + names[1] + " and " + str(length - 2) + " others like this",
+    ]
+    return text[length - (length > 3) * (length - 4)]

src/count_ip_addresses.py

@@ -0,0 +1,7 @@
+def ips_between(start, end):
+    start_a = start.split(".")
+    end_a = end.split(".")
+    difference = 0
+    for index, i in enumerate(start_a):
+        difference += (int(end_a[index]) - int(i)) * 256 ** (3 - index)
+    return difference