diff --git a/gen-Python b/gen-Python
new file mode 100755
index 0000000..44f45f4
--- /dev/null
+++ b/gen-Python
@@ -0,0 +1,2 @@
+echo "python3 main.py" > test_memory_Python
+chmod +x test_memory_Python
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..2934776
--- /dev/null
+++ b/main.py
@@ -0,0 +1,38 @@
+
+
+
+# L4: Function.
+
+def memory_generateConstPlayfield(
+  n: int
+) -> dict[int, int]:
+  idGroups: dict[int, int] = { }
+  id = 0
+  for gid in range(0, n):
+    idGroups[id] = gid
+    id += 1
+    idGroups[id] = gid
+    id += 1
+  #}
+  return idGroups
+#}
+
+# L20: Test.
+
+def test_memory_generateConstPlayfield() -> str:
+  idGroups = memory_generateConstPlayfield(2)
+  if (
+    len(idGroups) == 4 and
+    idGroups[0] == 0 and
+    idGroups[1] == 0 and
+    idGroups[2] == 1 and
+    idGroups[3] == 1
+  ):
+    return "OK: memory_generateConstPlayfield"
+  #}
+  return "ERR: memory_generateConstPlayfield"
+#}
+
+# L36: Run.
+
+print(test_memory_generateConstPlayfield())
diff --git a/main.swift b/main.swift
index 3a584d8..604156f 100644
--- a/main.swift
+++ b/main.swift
@@ -1,7 +1,7 @@
 
 
 
-// L4: Function
+// L4: Function.
 
 func memory_generateConstPlayfield(
   _ n: Int