move import statements below headers

Author: rlanzafame

book/beyond/nutshell/functions.ipynb

@@ -1,15 +1,5 @@
 {
  "cells": [
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "from math import pi \n",
-    "import os "
-   ]
-  },
   {
    "attachments": {},
    "cell_type": "markdown",
@@ -22,6 +12,16 @@
     "Here's an example that showcases the difference between lambda functions and normal functions:"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from math import pi \n",
+    "import os "
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 6,

book/beyond/nutshell/strings.ipynb

@@ -1,22 +1,22 @@
 {
  "cells": [
   {
-   "cell_type": "code",
-   "execution_count": 1,
+   "attachments": {},
+   "cell_type": "markdown",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "from math import pi \n",
-    "import os "
+    "# Beyond the Basics: Strings\n",
+    "In Python, <b><code>strings</code></b> are created using quotes ('' or \"\") and are immutable, while <b><code>f-strings</code></b> are formatted strings that allow embedding expressions inside curly braces { } for dynamic value substitution during runtime. Here is a couple of examples for strings:"
    ]
   },
   {
-   "attachments": {},
-   "cell_type": "markdown",
+   "cell_type": "code",
+   "execution_count": null,
    "metadata": {},
+   "outputs": [],
    "source": [
-    "# Beyond the Basics: Strings\n",
-    "In Python, <b><code>strings</code></b> are created using quotes ('' or \"\") and are immutable, while <b><code>f-strings</code></b> are formatted strings that allow embedding expressions inside curly braces { } for dynamic value substitution during runtime. Here is a couple of examples for strings:"
+    "from math import pi \n",
+    "import os "
    ]
   },
   {