Fix EMA calculation for window size 1

ciphers/des_ecb.py

@@ -537,21 +537,26 @@ def decrypt(key: str, cipher_text: str) -> str:
         if mode not in ["e", "d", "k", "q"]:
             print("Invalid option. Please try again.")
             continue
-        if mode == "q":
-            break
-        elif mode == "k":
-            print(f"Generated key: {Des.generate_key()}")
-        elif mode == "e":
-            key = input("Enter the key: ").strip()
-            if len(key) != 16 and not all(char in "0123456789abcdef" for char in key):
-                print("Invalid key. Please try again.")
-                continue
-            input_string = input("Enter the string to encrypt: ").strip()
-            print(f"Encrypted string: {Des.encrypt(key, input_string)}")
-        elif mode == "d":
-            key = input("Enter the key: ").strip()
-            if len(key) != 16 and not all(char in "0123456789abcdef" for char in key):
-                print("Invalid key. Please try again.")
-                continue
-            cipher_text = input("Enter the cipher text to decrypt: ").strip()
-            print(f"Decrypted string: {Des.decrypt(key, cipher_text)}")
+        match mode:
+            case "q":
+                break
+            case "k":
+                print(f"Generated key: {Des.generate_key()}")
+            case "e":
+                key = input("Enter the key: ").strip()
+                if len(key) != 16 and not all(
+                    char in "0123456789abcdef" for char in key
+                ):
+                    print("Invalid key. Please try again.")
+                    continue
+                input_string = input("Enter the string to encrypt: ").strip()
+                print(f"Encrypted string: {Des.encrypt(key, input_string)}")
+            case "d":
+                key = input("Enter the key: ").strip()
+                if len(key) != 16 and not all(
+                    char in "0123456789abcdef" for char in key
+                ):
+                    print("Invalid key. Please try again.")
+                    continue
+                cipher_text = input("Enter the cipher text to decrypt: ").strip()
+                print(f"Decrypted string: {Des.decrypt(key, cipher_text)}")

financial/exponential_moving_average.py

@@ -19,6 +19,9 @@ def exponential_moving_average(
     Yields exponential moving averages of the given stock prices.
     >>> tuple(exponential_moving_average(iter([2, 5, 3, 8.2, 6, 9, 10]), 3))
     (2, 3.5, 3.25, 5.725, 5.8625, 7.43125, 8.715625)
+    >>> tuple(exponential_moving_average(iter([10.0, 20.0, 30.0]), 1))
+    (10.0, 20.0, 30.0)
+
 
     :param stock_prices: A stream of stock prices
     :param window_size: The number of stock prices that will trigger a new calculation
@@ -49,7 +52,7 @@ def exponential_moving_average(
     moving_average = 0.0
 
     for i, stock_price in enumerate(stock_prices):
-        if i <= window_size:
+        if i < window_size:
             # Assigning simple moving average till the window_size for the first time
             # is reached
             moving_average = (moving_average + stock_price) * 0.5 if i else stock_price