You use the Python interpreter every single day. It does a lot of things for you: checks that your code has valid syntax and is properly indented, imports modules from various locations, and runs your code instruction-by-instruction.

But if you've ever wondered how exactly it happens, this talk will teach you the entire process, by building a working python interpreter from scratch.

The plan is to write a really simple, but working Python interpreter that can run Python code, from scratch.

The topics we'll be going through to build this interpreter:

• Lexing an indentation based language
  • Why Indent and Dedent need to be tokens
• Writing a Recursive Descent parser
  • Parsing literals: ints, strings, lists, dictionaries
  • Parsing expressions
  • Parsing function calls - print("Hello world!")
• Semantic analysis: removing invalid code
• A tree-walk interpreter
  • Interpreting print() statements
  • Running import statements
  • File I/O: implementing open() calls
• Running json.loads() and json.dumps() from scratch