Add finalized butterfly pattern implementation and test

graphics/butterfly_pattern.py

@@ -1,16 +1,27 @@
-def butterfly_pattern(n):
+def butterfly_pattern(n: int) -> str:
+    """
+    Creates a butterfly pattern of size n and returns it as a string.
+    """
+    result = []
+
     # Upper part
     for i in range(1, n + 1):
-        print("*" * i, end="")
-        print(" " * (2 * (n - i)), end="")
-        print("*" * i)
+        left_stars = "*" * i
+        spaces = " " * (2 * (n - i + 2))
+        right_stars = "*" * i
+        result.append(left_stars + spaces + right_stars)
 
     # Lower part
     for i in range(n - 1, 0, -1):
-        print("*" * i, end="")
-        print(" " * (2 * (n - i)), end="")
-        print("*" * i)
+        left_stars = "*" * i
+        spaces = " " * (2 * (n - i + 2))
+        right_stars = "*" * i
+        result.append(left_stars + spaces + right_stars)
+
+    return "\n".join(result)
+
 
+if __name__ == "__main__":
+    n = int(input("Enter the size of the butterfly pattern: "))
+    print(butterfly_pattern(n))
 
-n = int(input("Enter the size: "))
-butterfly_pattern(n)

graphics/test_butterfly_pattern.py

@@ -0,0 +1,11 @@
+from graphics.butterfly_pattern import butterfly_pattern
+
+def test_butterfly_pattern():
+    expected_output = (
+        "*        *\n"
+        "**      **\n"
+        "***    ***\n"
+        "**      **\n"
+        "*        *"
+    )
+    assert butterfly_pattern(3) == expected_output