add training/syntax_only.ipynb — kernel + Python syntax only (no project logic)

training/syntax_only.ipynb

@@ -0,0 +1,105 @@
+{
+  "nbformat": 4,
+  "nbformat_minor": 4,
+  "metadata": {
+    "kernelspec": {
+      "display_name": "Python 3",
+      "language": "python",
+      "name": "python3"
+    },
+    "language_info": {
+      "name": "python",
+      "version": "3.10.0"
+    }
+  },
+  "cells": [
+    {
+      "cell_type": "markdown",
+      "metadata": {},
+      "source": [
+        "# `syntax_only.ipynb`\n",
+        "\n",
+        "**Purpose:** confirm the notebook kernel runs and Python **syntax** is valid.\n",
+        "\n",
+        "- No app logic, no repo imports, no training.\n",
+        "- Run **Run all**; every cell should complete without error."
+      ]
+    },
+    {
+      "cell_type": "code",
+      "metadata": {},
+      "execution_count": null,
+      "outputs": [],
+      "source": [
+        "# Cell 1 — stdlib only\n",
+        "import ast\n",
+        "import json\n",
+        "import sys\n",
+        "from pathlib import Path\n",
+        "\n",
+        "print(\"Python:\", sys.version.split()[0])\n",
+        "print(\"OK: stdlib imports\")"
+      ]
+    },
+    {
+      "cell_type": "code",
+      "metadata": {},
+      "execution_count": null,
+      "outputs": [],
+      "source": [
+        "# Cell 2 — language syntax (no domain code)\n",
+        "x = [n * 2 for n in range(3)]\n",
+        "d = {\"a\": 1, **{\"b\": 2}}\n",
+        "y = (n := 1) + 1\n",
+        "\n",
+        "match y:\n",
+        "    case 2:\n",
+        "        z = \"two\"\n",
+        "    case _:\n",
+        "        z = \"other\"\n",
+        "\n",
+        "assert x == [0, 2, 4] and d[\"b\"] == 2 and z == \"two\"\n",
+        "print(\"OK: comprehensions, dict unpack, walrus, match\")"
+      ]
+    },
+    {
+      "cell_type": "code",
+      "metadata": {},
+      "execution_count": null,
+      "outputs": [],
+      "source": [
+        "# Cell 3 — parse a multi-line string (syntax check only)\n",
+        "src = \"\"\"\n",
+        "def _demo(a: int) -> str:\n",
+        "    return f\"v={a}\"\n",
+        "\"\"\"\n",
+        "ast.parse(src)\n",
+        "compile(src, \"<syntax_only>\", \"exec\")\n",
+        "print(\"OK: ast.parse + compile\")"
+      ]
+    },
+    {
+      "cell_type": "code",
+      "metadata": {},
+      "execution_count": null,
+      "outputs": [],
+      "source": [
+        "# Cell 4 — optional third-party imports (skip if not installed)\n",
+        "_optional = [\"numpy\", \"torch\", \"transformers\", \"pydantic\"]\n",
+        "for name in _optional:\n",
+        "    try:\n",
+        "        __import__(name)\n",
+        "        print(\"OK:\", name)\n",
+        "    except ImportError:\n",
+        "        print(\"(skip)\", name, \"— not installed\")"
+      ]
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {},
+      "source": [
+        "If every code cell printed `OK`, your kernel and basic syntax path are fine. Use `train_grpo_smoke.ipynb` for repo/env checks."
+      ]
+    }
+  ]
+}