01_PYTHONPATH.md

We will start with a simple module:

• Open a terminal window and move to a working directory (this directory will be called WORDIR during this tutorial
• Create a file named calculator.py with the following content:

  """
  Calculator module
  """
  
  class Calculator():
      """
      Calculator class implementing simple operations
      """
  
      def add(self, a, b):
          """
          Returns the addition of a with b
          """
          return a-b
  

• In another terminal, move to your home directory and try to import the newly created module with python3 -c "import calculator".
• Python is not able to found your module, now you can set export PYTHONPATH=$PYTHONPATH:WORKDIR and try again to import your module.

This technique is acceptable for small independent modules that belong to us and that we can then place in a personal directory with a PYTHONPAH setting in the .bash_profile file. But how do we manage projects that are a little larger, or that we want to share?

Next step here.