Learning Objectives

Jupyter Notebook - Markdown Cells - Markdown cell displays text which can be formatted using markdown language. In order to enter a text which should not be treated as code by Notebook server, it. The Jupyter Notebook is a web-based interactive computing platform. The notebook combines live code, equations, narrative text, visualizations, interactive dashboards and other media. You can attach image files directly to a notebook in Markdown cells by dragging and dropping it into the cell. To add images to other cell types, use graphics that are hosted on the web with this code, substituting url/name with the full URL and name of the image.

After completing this page, you will be able to:

• Create new Code and Markdown cells within Jupyter Notebook.
• Run Code and Markdown cells within Jupyter Notebook to execute Python code and render Markdown text.
• List useful shortcuts for common tasks in Jupyter Notebook.

Work With Python Code and Markdown Cells in Jupyter Notebook

Recall that a Jupyter Notebook file consists of a set of cells that can store text or code.

• Text Cells: Text cells allow you to write and render Markdown syntax. This is where you can describe and document your workflow.
• Code Cells: Code cells allow you to write and run programming code (e.g. Python).

Create New Cells

You can use either the Menu tools or Keyboard Shortcuts to create new cells.

While the default cell type for new cells is Code, you can change the cell type of any existing cell by clicking in the cell and selecting a new cell type (e.g. Markdown) in the cell type menu in the toolbar.

Cell type options include Code, Markdown, Raw NBConvert (for text to remain unmodified by nbconvert), and Heading.

To use the Keyboard Shortcuts, hit the esc key. After that, you can change a cell to Markdown by hitting the m key, or you can change a cell to Code by hitting the y key.

Run Cells

Python Code Cells

You can run any cell in Jupyter Notebook (regardless of whether it contains Code or Markdown) using the Menu tools or Keyboard Shortcuts.

For example, you can add a new Code cell and then run the following Python code (e.g. 3 + 4). Your result, or output, will be displayed below the Code cell that you run.

Markdown Cells

You can run Markdown cells in the same way that you can run code cells. However, when you run a Markdown cell, the text formatted using Markdown syntax will be rendered as stylized text.

This means that headings are larger and bold, bulleted lists have bullets next to them instead of *, and regular text looks normal. No outputs will appear below the Markdown cell.

For example, the Markdown syntax below represents 3 headers. You can double-click in any Markdown cell to see the raw Markdown syntax, which for the cell below would appear like this raw Markdown syntax:

To see the Markdown as stylized text, run the cell. It should look like the text printed below:

This is a subtitle in Markdown

This is a smaller subtitle

This is an even smaller subtitle

Rearrange Cells in a Jupyter Notebook

You can change the order of cells within Jupyter Notebook using the up arrow and down arrow buttons on the menu bar. To do this, click inside the cell that you want to move and then press the desired arrow as many times as you need to move the Cell to the desired location.

Clear Results in Jupyter Notebook

Sometimes, you may want to clear any output results that have been produced. You can do this using the Menu:

This will clear the current cell that you are working in, which you can activate by clicking in a cell.

You can also clear all of the output using the Menu Tools.

Learning Objectives

• Explain what the Markdown format is.
• Describe the role of Markdown for documentation of earth data science workflows.
• Use Markdown syntax in Jupyter Notebook to:
  • Create headers and lists
  • Bold and italicize bold text
  • Render images and create hyperlinks to web pages

What is Markdown?

Markdown is a human readable syntax (also referred to as a markup language) for formatting text documents. Markdown can be used to produce nicely formatted documents including PDFs and web pages.

When you format text using Markdown in a document, it is similar to using the format tools (e.g. bold, heading 1, heading 2) in a word processing tool like Microsoft Word or Google Docs. However, instead of using buttons to apply formatting, you use syntax such as **this syntax bolds text in markdown** or # Here is a heading.

Markdown syntax allows you to format text in many ways, such as making headings, bolding and italicizing words, creating bulleted lists, adding links, formatting mathematical symbols and making tables. These options allow you to format text in visually appealing and organized ways to present your ideas.

You can use Markdown to format text in many different tools including GitHub.com, R using RMarkdown, and Jupyter Notebook, which you will learn more about this page.

Data Tip: Learn more about how you can use Markdown to format text and document workflows in a variety of tools.

Markdown in Jupyter Notebook

A great benefit of Jupyter Notebook is that it allows you to combine both code (e.g. Python) and Markdown in one document, so that you can easily document your workflows.

A Jupyter Notebook file uses cells to organize content, and it can contain both cells that render text written using the Markdown syntax as well as cells that contain and run Python code.

Thus, you can use a combination of Markdown and Python code cells to organize and document your Jupyter Notebook for others to easily read and follow your workflow.

Add Markdown To Jupyter Notebook

Data Tip: Learn more about Markdown for Jupyter Notebook.

If you render your Jupyter Notebook file to HTML or PDF, this Markdown will appear as formatted text in the output document.

Data Tip: In fact, this web page that you are reading right now is generated from a Markdown document! On this page, you will learn the basic syntax of Markdown.

Benefits of Markdown for Earth Data Science

Being able to include both Markdown and code (e.g. Python) cells in a Jupyter Notebook file supports reproducible science by allowing you to:

• Document your workflow: You can add text to the document that describes the steps of your processing workflow (e.g. how data is being processed and what results are produced).
• Describe your data: You can describe the data that you are using (e.g. source, pre-processing, metadata).
• Interpret code outputs: You can add some text that interprets or discusses the outputs.

all in one document!

When used effectively, Markdown documentation can help anyone who opens your Jupyter Notebook to follow, understand and even reproduce your workflow.

Format Text in Jupyter Notebook with Markdown

Markdown Cells in Jupyter Notebook

In the previous chapter on Jupyter Notebook, you learned how to add new Markdown cells to your Jupyter Notebook files using Menu tools and Keyboard Shortcuts to create new cells.

You also learned how to change the default type of the cell by clicking in the cell and selecting a new cell type (e.g. Markdown) in the cell type menu in the toolbar. Furthermore, you learned that in a Jupyter Notebook file, you can double-click in any Markdown cell to see the syntax, and then run the cell again to see the Markdown formatting.

Note: if you type text in a Markdown cell with no additional syntax, the text will appear as regular paragraph text. You can add additional syntax to that text to format it in different ways.

On this page, you will learn basic Markdown syntax that you can use to format text in Jupyter Notebook files.

Section Headers

You can create a heading using the pound (#) sign. For the headers to render properly, there must be a space between the # and the header text.

Heading one is denoted using one # sign, heading two is denoted using two ## signs, etc, as follows:

Here is a sample of the rendered Markdown:

Heading Three

Heading Four

Note: the titles on this page are actually formatted using Markdown (e.g. the words Section Headers above are formatted as a heading two).

Lists

You can also use Markdown to create lists using the following syntax:

It will render as follows:

• This is a bullet list
• This is a bullet list
• This is a bullet list

1. And you can also create ordered lists
2. by using numbers
3. and listing new items in the lists
4. on their own lines

Notice that you have space between the * or 1. and the text. The space triggers the action to create the list using Markdown.

Bold and Italicize

You can also use ** to bold or * to italicize words. To bold and italicize words, the symbols have to be touching the word and have to be repeated before and after the word using the following syntax:

It will render as follows:

Jupyter Notebook Shortcut To Markdown

These are italicized words, not a bullet listThese are bold words, not a bullet list

• This is a bullet item with bold words
• This is a bullet item with italicized words

Highlight Code

If you want to highlight a function or some code within a plain text paragraph, you can use one backtick on each side of the text like this:

which renders like this:

Here is some code!

The symbol used is the backtick, or grave; not an apostrophe (on most US keyboards, it is on the same key as the tilde (~)).

Horizontal Lines (Rules)

You can also create a horizontal line or rule to highlight a block of Markdown syntax (similar to the highlighting a block of code using the backticks):

which renders like this:

Here is some important text!

Hyperlinks

You can also use HTML in Markdown cells to create hyperlinks to websites using the following syntax:

<a href='url' target='_blank'>hyperlinked words</a>

You can identify the words that will be hyperlinked (i.e. prompt a web page to open when clicked) by replacing hyperlinked words in the example above.

For example, the following syntax:

Our program website can be found at <a href='http://earthdatascience.org' target='_blank'>this link</a>.

will render as follows with this link as the hyperlinked words:

Our program website can be found at this link.

Render Images

You can also use Markdown to link to images on the web using the following syntax:

![alt text here](url-to-image-here)

The alt text is the alternative text that appears if an image fails to load on webpage; it is also used by screen-reading tools to identify the image to users of the screen-reading tools.

For example, the following syntax:

![Markdown Logo is here.](https://www.fullstackpython.com/img/logos/markdown.png)

Jupiter Notebook To Markdown Excel

will render as follows with an alt text of Markdown Logo is here.:

Local Images Using Relative Computer Paths

You can also add images to a Markdown cell using relative paths to files in your directory structure using:

![alt text here](path-to-image-here)

For relative paths (images stored on your computer) to work in Jupyter Notebook, you need to place the image in a location on your computer that is RELATIVE to your .ipynb file. This is where good file management becomes extremely important.

For a simple example of using relative paths, imagine that you have a subdirectory named images in your earth-analytics directory (i.e. earth-analytics/images/).

Jupiter Notebook To Markdown Pdf

If your Jupyter Notebook file (.ipynb) is located in root of this directory (i.e. earth-analytics/notebook.ipynb), and all images that you want to include in your report are located in the images subdirectory (i.e. earth-analytics/images/), then the path that you would use for each image is:

images/image-name.png

If all of your images are in the images subdirectory, then you will be able to easily find them. This also follows good file management practices because all of the images that you use in your report are contained within your project directory.

Data tip: There are many free Markdown editors out there! The atom.io editor is a powerful text editor package by GitHub, that also has a Markdown renderer that allows you to preview the rendered Markdown as you write.

Additional Resources

Practice Your Markdown Skills

1. Open or create a new Jupyter Notebook file.

2. Add a new Markdown cell and include:
   • A title for the notebook (e.g. Intro to Earth Analytics - Chapter Four)
   • A bullet list with:
     • A bold word for Author: and then add text for your name.
     • A bold word for Date: and then add text for today’s date.
3. Add another Markdown cell and include:
   • A list of your top three favorite foods (e.g. blueberries, chocolate bars, avocados).
     • Italicize the first item in your list.
     • Add a hyperlink (i.e. webpages) for the second item in your list (include the name of the food in the title of the hyperlink).
     • Add an image for the last item in your list (include the name in the alt text of the image).