Return to Table of Contents

Jupyter Line and Cell Magics, and IPython Syntax

In addition to running Python code, Jupyter Notebooks allows users to run magic commands with various functionality. While all magic commands are available to users, the below magic commands are used the most in the OpenScienceLab:

• Shell Assignment Syntax
• Line Magics
• Cell Magics

---

Shell Assignment Syntax

In IPython syntax, the exclamation mark (!) allows users to run shell commands from inside a Jupyter Notebook code cell.

Simply start a line of code with ! and it will run the command in the shell.

Example:

---

Line Magics

Line magics start with a single % sign and affect only the line where % is used.

The following are the most frequently used line magics:

%matplotlib inline

• Allows non-interactive matplotlib plots to be displayed in a notebook.

Example:

%matplotlib widget

• Allows interactive matplotlib plots to be displayed and interacted with inside a Jupyter Notebook.

Example:

%df

This is a custom magic written specifically for OpenScienceLab. It uses the Python function shutil.disk_usage() to check the storage state of the user's volumes.

You may use the below flags to output results in a different manner:

• %df - Returns a human-readable string in GB.
• %df --raw - Returns a raw data object.
• %df --on - Returns a string in GB after running every subsequent code cell.
• %df --off - Turns off the %df --on option.
• %df -v - Prints additional debugging text.

Example:

Legacy Note

Due to the new url_widget package, the user no longer needs to use the %matplotlib notebook and use the %matplotlib widget instead.

---

Cell Magics

Cell magics start with %% and affect the contents of an entire cell.

%%javascript (or %%js)

• Runs a JavaScript code cell.

Note: leave a blank line above the magic command in the beginning of the code cell.

Example:

%%capture

• Runs the cell but captures all output. We typically use this to suppress the output of a %matplotlib plot that the user does not wish to see.