Disclaimer: Python is an extensive programming (or scripting) language. It is neither easy not effective to teach Python in a single webpage. The main purpose of this page is to create a shortcut to the commands that we use a lot during this course. We also provide links to nice Python tutorials if you are interested to improve your skills in Python programming.

Please look at and admire this website: https://docs.python.org

Running Python scripts

Let’s start a simple Python script:

print('Hello world')

Through Terminal

You can write it directly in your terminal:

  1. Open a terminal: Ctrl + Alt + T
  2. Type: python3
  3. Paste the code above.

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Or you can directly run Python scripts via terminal.

  1. Open a terminal: Ctrl + Alt + T
  2. Create a Python file: gedit my_first_python.py
  3. Save and close.
  4. Run: python3 my_first_python.py

Through VSCode

You need an IDE for more complicated code. We use VSCode.

  1. Open Visual Studio Code
  2. File > New File > Python file
  3. Paste the code above
  4. Run (play button rigth above).

Functions

Simple function:

def main():
    print('Hello world')

if __name__ == '__main__':
    main()

Call a function inside another function:

def main():
    my_print_function()

def my_print_function():
    print('Hello world')

if __name__ == '__main__':
    main()

Rarely you define a function inside a function (nested function):

def outerFunction(text): 
    text = text 
    
    def innerFunction(): 
        print(text) 
    
    innerFunction() 
    
if __name__ == '__main__': 
    outerFunction('Hello world')

Imports

Imports are libraries.

TODO:

  • Simple print
  • import and from
  • functions
  • import from other file
  • os, join path: https://www.geeksforgeeks.org/python-os-path-join-method/
    • This is particularly important for servo.py and XX.launch.py files.
    • glob: https://docs.python.org/3/library/glob.html
    • https://www.geeksforgeeks.org/how-to-use-glob-function-to-find-files-recursively-in-python/
  • classes
    • self
    • init constructor
    • methods
      • Just mention static and class methods
  • parenting
    • super()
  • Simple 3 exercises.

Useful materials:

Python books Websites Youtube videos