alexpeits / presentationlib

Tool for creating live presentations and evaluating Python code

presentationlib

Tool for live coding presentations

(I will find a better name)

presentationlib is a simple tool for doing presentations via the python REPL. It was inspired by these two talks by David Beazley.

It can easily present text files, but can also execute python files in the global scope, the same as if the presenter typed in the code or imported it.

The usage is simple, import the presentation function, declare a mapping to configure the files that are included in the presentation, and run it.

The mapping can also include a list. Then, multiple uses of it cycle through the options.

Usage

File structure:

|
|- run_presentation.py
|- slides/
    |- fib.py
    |- lorem.txt

run_presentation.py:

from presentationlib import presentation

mapping = {
    'fib': 'fib.py',
    'lorem': {'file': 'lorem.txt', 'wrap': True},
    'test': '~/file.txt',
    'multiple': [
        'fib.py',
        '~/file.txt',
        {'file': 'lorem.txt', 'wrap': True}
    ]
}

if __name__ == '__main__':
    presentation(
        mapping, location='slides',
        heading='My Presentation', subheading='waaaaat'
    )

Presentation:

$ python run_presentation.py

--------------------------------------------------

             My Presentation

--------------------------------------------------

                 waaaaat


>>> 'hello'
'hello'
>>> 'fib'
+------------------------------------------------------------------------------+
|                                                                              |
|  def fibo(lim):                                                              |
|      a, b = 0, 1                                                             |
|      while a <= lim:                                                         |
|          yield a                                                             |
|          a, b = b, a+b                                                       |
|                                                                              |
+------------------------------------------------------------------------------+

>>> fibo
<function fibo at 0x7faf003ac500>
>>> list(fibo(5))
[0, 1, 1, 2, 3, 5]
>>>
>>> 'lorem'
+------------------------------------------------------------------------------+
|                                                                              |
|  Lorem ipsum dolor sit amet, neque voluptatum pede nulla praesent, arcu      |
|  neque amet sit, cum libero quis gravida arcu, pellentesque amet per amet    |
|  mi. Justo sapien sit ut, sit arcu lobortis tincidunt, dolor elit lobortis   |
|  gravida. At at leo egestas est, alias libero nisl nam id, eleifend          |
|  interdum sagittis congue eiusmod. Rutrum ante rutrum mauris, lorem aliquet  |
|  placerat sollicitudin alias, tenetur dignissim accusantium elit eros, dui   |
|  suscipit lacus ut. Wisi sodales exercitationem nullam, non in nunc eget.    |
|  Sapien eu volutpat felis ac, nibh cursus elit varius.                       |
|                                                                              |
+------------------------------------------------------------------------------+

>>> 'multiple'
+------------------------------------------------------------------------------+
|                                                                              |
|  def fibo(lim):                                                              |
|      a, b = 0, 1                                                             |
|      while a <= lim:                                                         |
|          yield a                                                             |
|          a, b = b, a+b                                                       |
|                                                                              |
+------------------------------------------------------------------------------+

>>> 'multiple'
+------------------------------------------------------------------------------+
|                                                                              |
|  This is a file                                                              |
|  Yes, this is a file                                                         |
|                                                                              |
+------------------------------------------------------------------------------+

>>> 'multiple'
+------------------------------------------------------------------------------+
|                                                                              |
|  Lorem ipsum dolor sit amet, neque voluptatum pede nulla praesent, arcu      |
|  neque amet sit, cum libero quis gravida arcu, pellentesque amet per amet    |
|  mi. Justo sapien sit ut, sit arcu lobortis tincidunt, dolor elit lobortis   |
|  gravida. At at leo egestas est, alias libero nisl nam id, eleifend          |
|  interdum sagittis congue eiusmod. Rutrum ante rutrum mauris, lorem aliquet  |
|  placerat sollicitudin alias, tenetur dignissim accusantium elit eros, dui   |
|  suscipit lacus ut. Wisi sodales exercitationem nullam, non in nunc eget.    |
|  Sapien eu volutpat felis ac, nibh cursus elit varius.                       |
|                                                                              |
+------------------------------------------------------------------------------+

Configuration options

• location: the directory in which all filenames are searched (except for absolute paths)
• exec_py: whether python files are executed to make functions, classes and variables available in the REPL
• use_box: whether to put text inside an ascii box
• box_width: the box width to use, if use_box is True
• banner: printed on REPL initialization (a default banner is also provided)
• heading and subheading: banner can be a template, these are the template options

How does it work?

The printing of file content when the user inputs a simple string works by patching sys.displayhook. This is a function that is ran in the interactive REPL whenever a user wants to output something (not when using print).

The execution of the python files is made possible by using frame inspection. The modified displayhook gets the caller's frame, and executes the code inside the REPL's context. Note that any code outside an if __name__ == '__main__' guard will be executed.