Useful IPython magic commands

In this article, we will cover IPython Magic commands/functions and discuss various types of magic commands available. In this article we will be using Jupyter Notebook to execute the magic commands first, we look at what are Magic functions and why we use them, then different types of magic functions followed by examples. There are a lot of magic functions but in this article, we discuss the most commonly used magic functions.

Jupyter Notebook

The Jupyter Notebook is the original web application for creating and sharing computational documents that contain live code, equations, visualizations, and narrative text. It offers a simple, streamlined, document-centric experience. Jupyter has support for over 40 different programming languages and Python is one of them.

Magic Commands

Magic commands generally known as magic functions are special commands in IPython that provide special functionalities to users like modifying the behavior of a code cell explicitly, simplifying common tasks like timing code execution, profiling, etc. Magic commands have the prefix '%' or '%%' followed by the command name. There are two types of magic commands:

1. Line Magic Commands
2. Cell Magic Commands

Line Magic Commands

Line magic commands are used to provide a special functionality to a single line of code, line magic commands begin with '%' followed by the line command. To check the available magic commands run '%lsmagic' this command will show all the magic commands, as of now there are 97 line magic commands which are as follows:

%alias, %alias_magic, %autoawait, %autocall, %automagic, %autosave, %bookmark, %cat, %cd, %clear, %colors, %conda, %config, %connect_info, %cp, %debug, %dhist, %dirs, %doctest_mode, %ed, %edit, %env, %gui, %hist, %history, %killbgscripts, %ldir, %less, %lf, %lk, %ll, %load, %load_ext, %loadpy, %logoff, %logon, %logstart, %logstate, %logstop, %ls, %lsmagic, %lx, %macro, %magic, %man, %matplotlib, %mkdir, %more, %mv, %notebook, %page, %pastebin, %pdb, %pdef, %pdoc, %pfile, %pinfo, %pinfo2, %pip, %popd, %pprint, %precision, %prun, %psearch, %psource, %pushd, %pwd, %pycat, %pylab, %qtconsole, %quickref, %recall, %rehashx, %reload_ext, %rep, %rerun, %reset, %reset_selective, %rm, %rmdir, %run, %save, %sc, %set_env, %store, %sx, %system, %tb, %time, %timeit, %unalias, %unload_ext, %who, %who_ls, %whos, %xdel, %xmode

Since it is not possible to cover all the 97 line magic commands we will only cover the most widely and helpful commands in this article, we will look some line magic commands along with the short description followed by example of some line magic commands:

Example of Line Magic Functions

1. %load

• Load the code from external file and insert in into the cell
• Syntax:

%load file_name.py

Example:

%load fibo.py

2. %run

• Run the named file inside IPython as a program
• Syntax:

%run file_name.py

Example:

%run tricks.py

Output:

3. %time

• Measure the execution time of a single Python statement or expression
• Syntax:

%time some_funtion()

Example:

def fibonacci(n):
     if n == 0 or n == 1: return n
     return fibonacci(n-1)+fibonacci(n-2)
%time fibonacci(10)

Output:

CPU times: total: user 20 ns, sys:4 ns, total: 24 ns
Wall time: 26.2 ns
55

4. %timeit

• Measure the execution time of a single Python statement or expression by performing executions multiple time to get more accurate results.
• Syntax:

%timeit some_function()

Example:

def fibonacci(n):
     if n == 0 or n == 1: return n
     return fibonacci(n-1)+fibonacci(n-2)
%timeit fibonacci(10)

Output:

14.7 µs ± 869 ns per loop (mean ± std. dev. of 7 runs, 100,000 loops each)

5. %cd

• Change the current working directory
• Syntax:

%cd directory/sub_dir

Example:

%cd Form_data_visualization

Output:

Cell Magic Commands

Cell Magic functions are special commands that allow the user to modify the behavior of a code cell explicitly. Cell Magic functions have the prefix '%%' followed by the command name. Cell magic functions serve various tasks and customizations which we discuss thoroughly further in this article. As per the official python documentation there are 16 cell magic functions available now which are described below,

Since, its not possible to explain each cell magic command with example we will only cover some helpful and widely used cell magic commands.

Example of Cell Magic Functions

1. %%bash

Allows user to run Bash shell commands within the cell.

Example:

%%bash
ls -l

Output Screenshot:

2. %%html

This cell magic function renders contents of code cell as html script

Example:

%%html
<font size=10 color='hotpink'>Hello World</font>

Output Screenshot:

3. %%javascript or %%js

Allows you to execute JavaScript code within the cell

Example:

%%javascript
alert("This is a JavaScript alert!")

Output Screenshot:

4. %%latex

Renders LaTeX equations and expressions in the cell.

%%latex
$e^{i\pi} + 1 = 0$

Output Screenshot:

5. %%markdown or %%md

Renders the content of the cell as Markdown

Example:

%%markdown
# This is a Markdown Heading
* This is a bullet point

Output Screenshot: