widget_playground fixes

Author: slayoo

examples/widgets_playground.ipynb

@@ -17,7 +17,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "!pip install --quiet ipywidgets"
+    "import subprocess\n",
+    "for package in ('ipywidgets', 'matplotlib'):\n",
+    "    subprocess.check_call([sys.executable, \"-m\", \"pip\", \"install\", \"--quiet\", package])"
    ]
   },
   {
@@ -26,12 +28,10 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "import PyPartMC as ppmc\n",
     "from ipywidgets import Tab, SelectMultiple, IntSlider, FloatSlider, HTML, HBox, VBox, Output\n",
     "from matplotlib import pyplot\n",
-    "from IPython.display import display, clear_output\n",
-    "\n",
-    "%matplotlib widget"
+    "from IPython.display import display\n",
+    "import PyPartMC as ppmc"
    ]
   },
   {
@@ -40,14 +40,16 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "%matplotlib widget\n",
+    "\n",
     "if \"google.colab\" in sys.modules:\n",
-    "    hack = (\n",
+    "    HACK = (\n",
     "        \"<link\"\n",
     "        ' rel=\"stylesheet\"'\n",
     "        ' href=\"https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css\"'\n",
     "        \"> \"\n",
     "    )\n",
-    "    display(HTML(hack))"
+    "    display(HTML(HACK))"
    ]
   },
   {
@@ -126,7 +128,7 @@
     {
      "data": {
       "application/vnd.jupyter.widget-view+json": {
-       "model_id": "1eeaf25a187441b0a2d4ff0e16158319",
+       "model_id": "c9630f899d514ecb9c13641d56706dde",
        "version_major": 2,
        "version_minor": 0
       },
@@ -161,14 +163,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 12,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "[\"H2SO4\",\"HNO3\",\"HCl\",\"NO\",\"NO2\"]\n"
+      "[\"H2SO4\",\"HNO3\",\"HCl\",\"NH3\",\"NO\",\"NO2\"]\n"
      ]
     }
    ],