#!/usr/bin/env python
# coding: utf-8

# # Running Python in Jupyter Notebook

# There are different ways to execute Python script. Most common ways:
# 
# - 🖥 Running Python script in terminal/command line in Computer.
# - ⚙️ Running Python script in command line in Server.
# - 🤖 Running Python script in command line in embedded system.
# - 📒 Running Python code snippets in Jupyter Notebook.
# - 📟 Turnning Python script into exe and execute in Windows.
# - 📱 Running Python in iOS and ipadOS.
# - 📳 Running Python in Android.
# - 🔁 An intergration of methods above with other systems, such as Windows Scheduler, iOS Widget, Siri Shortcut.

# ## 📒 An introduction to running code in Jupyter notebook

# In this notebook, we explore how to use Jupyter Notebook to run Python code.

# For example, the following code output the reuslt of the calculation

# In[1]:


1+2


# In Jupyter notebook, code is spearated into `cells`.

# In[2]:


example = "This is another cell"


# Jupyter notebook shows the result of last line of each cell, if it is not a variable assignment. We call it "Inspection".

# **Cell** is the most special thing in Jupyter notebook.

# 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.

# In[3]:


example


# 👆🏻 See? We can inspect `example` variable that is stored previously.

# 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.
# 
# Now here is the code that asks for input.

# In[4]:


name = input("What is your name? ")
print(f"Hello {name} :-)")


# ## ⌨️ Using Jupyter Notebook via Keyboards

# 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.

# ### Moving up and down

# Moving selection up and down.
# 
# - You can move the selection up by using `up arrow` or `K`.
# - You can move the selection down by using `down arrow` or `J`.
# 

# ### Editing cell

# `ENTER` to edit the current selected cell.

# 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.

# ### Executing cell

# Here are some keyboard shortcuts.

# `CTRL+ENTER` to execute the current cell.
# 
# `SHIFT+ENTER` to execute the current cell and move to next cell

# ### Code or Markdown

# There are mainly two types of cells: **Code** and **Markdown**.

# Code is for Python execution and Markdown is for copy writings.
# 
# - You can toggle a cell into Markdown by pressing `M`.
# - You can toggle a cell into Code by pressing `Y`.

# ### Inserting cells

# Inserting cells below or above the current selection.
# 
# - We can use `A` to insert a cell above the current cell.
# - We can use `B` to insert a cell below the current cell.

# ## Summary
# 
# 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.