minor example edits

Author: lukebarousse

1_Basics/00_Intro_To_Programming.ipynb

@@ -80,27 +80,68 @@
     "90000"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "1ef640ba",
+   "metadata": {},
+   "source": [
+    "Everything in Python is an object; including functions and classes."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "4d55db87",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n"
+     ]
+    }
+   ],
+   "source": [
+    "print()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "aaa5da4b",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "str"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "str"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "fe74bb60",
    "metadata": {},
    "source": [
-    "### Variables: The Building Blocks\n",
+    "### Variables: The Reference to Objects\n",
     "\n",
     "Think of a variable as a cell in an Excel spreadsheet. You can store data in it, like a number, text, or a formula.\n",
     "\n",
     "**Variable**: A named cell that stores an object."
    ]
   },
-  {
-   "cell_type": "markdown",
-   "id": "f667cde9",
-   "metadata": {},
-   "source": []
-  },
   {
    "cell_type": "code",
-   "execution_count": 71,
+   "execution_count": 1,
    "id": "0fb0d189",
    "metadata": {},
    "outputs": [],
@@ -110,12 +151,120 @@
     "job_salary = 90000"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "a03cbbf0",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(4594639152, 4594645744, 4593144944)"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# each variable has a unique identifier\n",
+    "id(job_title), id(job_location), id(job_salary)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "864e8619",
+   "metadata": {},
+   "source": [
+    "Variables that reference the same object are the same."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "4b917379",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'Data Analyst'"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "lukes_job = job_title\n",
+    "\n",
+    "lukes_job"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "fc07b63c",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(4594639152, 4594639152)"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# the id of the same object is the same\n",
+    "id(job_title), id(lukes_job)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "f367a47d",
+   "metadata": {},
+   "source": [
+    "Variables may be assigned the same name, but aren't necessarily the same."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "a5aa7f31",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(4594562480, 4594554352)"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "job_title1 = \"Data Analyst\"\n",
+    "job_title2 = \"Data Analyst\"\n",
+    "\n",
+    "# the id of the same object is the same\n",
+    "id(job_title1), id(job_title2)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "c246c6c4",
    "metadata": {},
    "source": [
-    "### Functions: The General Tools\n",
+    "### Functions: The Manipulators of Objects\n",
     "\n",
     "Functions are like custom formulas in Excel. They perform tasks that can be applied to different sets of data.\n",
     "\n",