Python Programming

If you want to teach Python or at least run some Python snippets within your course, we currently recommend two different packages for LiaScript.

1. Pyodide
2. CodeRunner

What is the difference? Pyodide will load all libraries into your browser and execute it locally, while CodeRunner will compile and execute the code on a foreign server. The first project might cover only a reduced set of libraries, but it scales and adds plotting functionality, in contrast to the second one. In CodeRunner, plots can at the moment only be generated with R.

1. Pyodide

To use this functionality, you will have to import:

<!--
...
import: https://github.com/LiaTemplates/Pyodide/blob/0.1.4/README.md

-->

Afterwards you can attach the macro @Pyodide.eval to every Python-Code snippet.

Note: All scripts are executed in one global environment

Examples

import sys

for i in range(5):
	print("Hello", 'World #', i)

sys.version

@Pyodide.eval

---

Currently you can only plot one image, but this is shown within the terminal and also stored persitently. Thus, you can switch between different versions of your code and the resulting images will change too.

import numpy as np
import matplotlib.pyplot as plt

t = np.arange(0.0, 2.0, 0.01)
s = np.sin(2 * np.pi * t)

fig, ax = plt.subplots()
ax.plot(t, s)

ax.grid(True, linestyle='-.')
ax.tick_params(labelcolor='r', labelsize='medium', width=3)

plt.show()

plot(fig) # <- this is required to plot the fig also on the LiaScript canvas

@Pyodide.eval

NOTE: You can resize the terminal and you can click onto the image to enlarge it. The additional loading of libraries is only required once, then they are stored locally...

2. LiaScript Code-Runner

This allows, to run and execute your code on a real

<!--
...
import: https://github.com/LiaScript/CodeRunner/blob/master/README.md

-->

# ...

```python
for i in range(10):
  print "Hallo Welt", i
```
@LIA.eval(`["main.py"]`, `python -m compileall .`, `python main.pyc`)

Afterwards you can attach the macro @LIA.eval to every Python-Code snippet.

The @LIA.eval macro might look a bit cryptic, but it actually consists of three steps.

1. A list of filenames, if you use require more than one files for your project, then these have to be defined in order. A project can consist of multiple code-snippets attached to each other
2. A compilation command
3. A execution command

Example

for i in range(10):
  print "Hallo Welt", i

@LIA.eval(["main.py"], python -m compileall ., python main.pyc)

Best Practice

If you you have a couple of code-snippets and you do not want to add always the same complex macro, which might eventually change in the future. The best way is to define a custom macro, which defines the macro with all parameters. You can modify this in the future, just by changing the macro-definition an also the import. It is thus not required to change every macro separately:

<!--
...

import:   https://github.com/LiaTemplates/Pyodide/blob/0.1.4/README.md
          https://github.com/LiaScript/CodeRunner/blob/master/README.md

@@ can also be replaced by @Pyodide.eval
@eval:  @LIA.eval(`["main.py"]`, `python -m compileall .`, `python main.pyc`)

-->

# ...

```python
for i in range(10):
  print "Hallo Welt", i
```
@eval


```python
for i in range(10):
  print "Hello World", i
```
@eval

---

for i in range(10):
  print "Hallo Welt", i

@eval

for i in range(10):
  print "Hello World", i

@eval