diff --git a/1 python 基础.ipynb b/1 python 基础.ipynb
index 22bdabf..1963f8d 100644
--- a/1 python 基础.ipynb
+++ b/1 python 基础.ipynb
@@ -630,7 +630,7 @@
    "outputs": [],
    "source": [
     "a = [10, 11, 12]\n",
-    "a.append(['a','b'])\n",
+    "a.append(['a', 'b'])\n",
     "print (a)"
    ]
   },
@@ -649,7 +649,7 @@
    "outputs": [],
    "source": [
     "a = [10, 11, 12]\n",
-    "a.extend(['a','b'])\n",
+    "a.extend(['a', 'b'])\n",
     "print (a)"
    ]
   },
@@ -1275,6 +1275,7 @@
     "上面例子中的这两条语句：\n",
     "\n",
     "```python\n",
+    "\n",
     "print(\"Hey!\")   \n",
     "print(\"x is positive\")\n",
     "\n",
diff --git a/4 mnist_playground.ipynb b/4 mnist_playground.ipynb
index 3c36708..a771104 100644
--- a/4 mnist_playground.ipynb
+++ b/4 mnist_playground.ipynb
@@ -394,7 +394,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 5,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -498,7 +498,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 6,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -571,9 +571,122 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "3188bf852f504283a32ec8d9c36f8df6",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HTML(value='<h1>准备数据</h1>', placeholder='')"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "f699bee0823e4d44a63d633ffb325a37",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HBox(children=(VBox(children=(FloatSlider(value=0.0, continuous_update=False, description='每个 batch 内增强图片的比例:'…"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "20c9abfac7f942d09a0d899bd244156a",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HTML(value='<h1>构建模型</h1>', placeholder='')"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "0d8aee241fb7434ab7cdbbab38706072",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HBox(children=(VBox(children=(IntSlider(value=1, description='隐藏层数目:', layout=Layout(width='400px'), max=3, st…"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "4ee8896dd7f041fe8e1760a4039a7670",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HTML(value='<h1>训练模型</h1>', placeholder='')"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "6d3a35c6923c4f19b69d82e46942219e",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "SelectionSlider(continuous_update=False, description='训练轮数:', layout=Layout(width='400px'), options=(5, 10, 20…"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "1eed44ce2b764c2aa5a5083763a6e070",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "Button(button_style='info', description='开始训练', style=ButtonStyle(), tooltip='点击开始训练')"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "b4ff14fa4c61438d9e5d8ffa608e99a1",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "Output()"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    }
+   ],
    "source": [
     "mlp = NN()\n",
     "mlp.build_model()\n",
@@ -788,6 +901,13 @@
    "metadata": {},
    "outputs": [],
    "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {
diff --git a/data_sample.jpg b/data_sample.jpg
index ff94871..62b104e 100644
Binary files a/data_sample.jpg and b/data_sample.jpg differ
diff --git a/model.jpg b/model.jpg
new file mode 100644
index 0000000..fd628b3
Binary files /dev/null and b/model.jpg differ