Fix get_data.py detection

examples/workflow_by_code.ipynb

@@ -1,11 +1,11 @@
 {
  "cells": [
   {
+   "cell_type": "markdown",
+   "metadata": {},
    "source": [
     "<a href=\"https://colab.research.google.com/github/microsoft/qlib/blob/main/examples/workflow_by_code.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
-   ],
-   "cell_type": "markdown",
-   "metadata": {}
+   ]
   },
   {
    "cell_type": "code",
@@ -28,16 +28,17 @@
     "import sys, site\n",
     "from pathlib import Path\n",
     "\n",
-    "TEMP_CODE_DIR = str(Path(\"~/tmp/qlib_code\").expanduser().resolve())\n",
     "\n",
     "try:\n",
     "    import qlib\n",
-    "    scripts_dir = Path.cwd().parent.joinpath(\"scripts\")\n",
     "except ImportError:\n",
     "    # install qlib\n",
     "    ! pip install pyqlib\n",
     "    # reload\n",
     "    site.main()\n",
+    "\n",
+    "scripts_dir = Path.cwd().parent.joinpath(\"scripts\")\n",
+    "if not scripts_dir.joinpath(\"get_data.py\").exists():\n",
     "    # download get_data.py script\n",
     "    scripts_dir = Path(\"~/tmp/qlib_code/scripts\").expanduser().resolve()\n",
     "    scripts_dir.mkdir(parents=True, exist_ok=True)\n",
@@ -376,4 +377,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}