FIX: dynamically set mne_data_path with fallback to /tmp/mne_data in JupyterLite

Author: natinew77-creator

doc/conf.py

@@ -627,8 +627,13 @@
         "requests.Session.send = pyodide_send\n"
         "\n"
         "import os\n"
-        "os.environ['MNE_DATA'] = '/drive/mne_data'\n"
-        "os.environ['MNE_DATASETS_SAMPLE_PATH'] = '/drive/mne_data'\n"
+        "mne_data_path = (\n"
+        "    '/drive/mne_data' if os.path.exists('/drive/mne_data')\n"
+        "    else '/tmp/mne_data'\n"
+        ")\n"
+        "os.makedirs(mne_data_path, exist_ok=True)\n"
+        "os.environ['MNE_DATA'] = mne_data_path\n"
+        "os.environ['MNE_DATASETS_SAMPLE_PATH'] = mne_data_path\n"
         "\n"
         "# Intercept pooch to provide helpful errors for large OSF datasets\n"
         "orig_pooch_fetch = pooch.Pooch.fetch\n"
@@ -655,7 +660,7 @@
         "        pass\n"
         "for ds in ['SAMPLE', 'TESTING', 'SSVEP',"
         " 'EEGBCI', 'SOMATO', 'AUDIOVISUAL', 'BRAINSTORM']:\n"
-        "    mne.set_config(f'MNE_DATASETS_{ds}_PATH', '/drive/mne_data')\n"
+        "    mne.set_config(f'MNE_DATASETS_{ds}_PATH', mne_data_path)\n"
         "import IPython\n"
         "IPython.get_ipython().run_line_magic('matplotlib', 'inline')\n"
         "import matplotlib.pyplot as plt\n"