{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Running Python in Jupyter Notebook"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "There are different ways to execute Python script. Most common ways:\n",
    "\n",
    "- 🖥 Running Python script in terminal/command line in Computer.\n",
    "- ⚙️ Running Python script in command line in Server.\n",
    "- 🤖 Running Python script in command line in embedded system.\n",
    "- 📒 Running Python code snippets in Jupyter Notebook.\n",
    "- 📟 Turnning Python script into exe and execute in Windows.\n",
    "- 📱 Running Python in iOS and ipadOS.\n",
    "- 📳 Running Python in Android.\n",
    "- 🔁 An intergration of methods above with other systems, such as Windows Scheduler, iOS Widget, Siri Shortcut."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 📒 An introduction to running code in Jupyter notebook"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "In this notebook, we explore how to use Jupyter Notebook to run Python code."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "For example, the following code output the reuslt of the calculation"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "1+2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "In Jupyter notebook, code is spearated into `cells`."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "example = \"This is another cell\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Jupyter notebook shows the result of last line of each cell, if it is not a variable assignment. We call it \"Inspection\"."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Cell** is the most special thing in Jupyter notebook."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "In normal programming environment, code is executed **from top to bottom at once**. In Jupyter notebook, code execution is separated, but the state is kept."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'This is another cell'"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "example"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "👆🏻 See? We can inspect `example` variable that is stored previously."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can take input by using `input()` in Python. It works in Jupyter notebook too. And BE WARE that if you execute the cell twice before entering the input, you will make the kernel dead-loop. If the dead-loop happens, you may choose `kernel` > `Restart` to escape the dead-loop.\n",
    "\n",
    "Now here is the code that asks for input."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "What is your name? Thomas\n",
      "Hello Thomas :-)\n"
     ]
    }
   ],
   "source": [
    "name = input(\"What is your name? \")\n",
    "print(f\"Hello {name} :-)\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## ⌨️ Using Jupyter Notebook via Keyboards"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Jupyter notebook comes with some keyboard shortcuts for quicker operation without leaving the hands away from keyboard. In the following, I will show some essential keyboard shortcuts."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Moving up and down"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Moving selection up and down.\n",
    "\n",
    "- You can move the selection up by using `up arrow` or `K`.\n",
    "- You can move the selection down by using `down arrow` or `J`.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Editing cell"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "`ENTER` to edit the current selected cell."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The cell selection shows <font color=\"blue\"><b>blue</b></font> border by default. It turns into <font color=\"green\"><b>green</b></font> border when toggled into **editing** mode."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Executing cell"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Here are some keyboard shortcuts."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "`CTRL+ENTER` to execute the current cell.\n",
    "\n",
    "`SHIFT+ENTER` to execute the current cell and move to next cell"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Code or Markdown"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "There are mainly two types of cells: **Code** and **Markdown**."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Code is for Python execution and Markdown is for copy writings.\n",
    "\n",
    "- You can toggle a cell into Markdown by pressing `M`.\n",
    "- You can toggle a cell into Code by pressing `Y`."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Inserting cells"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Inserting cells below or above the current selection.\n",
    "\n",
    "- We can use `A` to insert a cell above the current cell.\n",
    "- We can use `B` to insert a cell below the current cell."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Summary\n",
    "\n",
    "In this notebook, we learned to operate Jupyter notebook and some keyboard shortcuts to master it. In next notebook, we will learn the Python variables."
   ]
  }
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