Add subinterpreters.py lesson

Author: huangsam

ultimatepython/advanced/subinterpreters.py

@@ -0,0 +1,51 @@
+"""
+Multi-interpreter support via concurrent.interpreters in Python 3.14 (PEP 734).
+
+Python subinterpreters allow running Python code in truly isolated
+environments within a single process. In Python 3.14, each interpreter
+has its own Global Interpreter Lock (GIL), enabling true multi-core
+parallelism for Python code.
+"""
+import concurrent.futures
+import concurrent.interpreters as interpreters
+
+
+def run_worker(data):
+    """Function to be run in a subinterpreter."""
+    # This code runs in a different interpreter environment
+    return f"Processed {data} in a subinterpreter"
+
+
+def main():
+    # 1. Create a subinterpreter
+    # The 'interpreters' module provides a high-level API
+    interp = interpreters.create()
+
+    assert isinstance(interp, interpreters.Interpreter)
+    assert interp.is_running() is False
+
+    # 2. Run code in the subinterpreter
+    # We can run simple strings of code
+    interp.exec("1 + 1")
+
+    # 3. Using InterpreterPoolExecutor for easier management
+    # This is similar to ThreadPoolExecutor or ProcessPoolExecutor
+    with concurrent.futures.InterpreterPoolExecutor(max_workers=2) as executor:
+        # Submit tasks to the pool
+        future1 = executor.submit(run_worker, "Task A")
+        future2 = executor.submit(run_worker, "Task B")
+
+        # Get results (this handles passing data back and forth)
+        result1 = future1.result()
+        result2 = future2.result()
+
+        assert result1 == "Processed Task A in a subinterpreter"
+        assert result2 == "Processed Task B in a subinterpreter"
+
+    # 4. Cleaning up
+    interp.close()
+    assert interp.id not in [i.id for i in interpreters.list_all()]
+
+
+if __name__ == "__main__":
+    main()