Execution model > Naming and binding > global:

appendExecution model > Naming and binding > global:
https://docs.python.org/3.6/reference/executionmodel.html

It would be impossible to assign to a global variable without global, although free variables may refer to globals without being declared global.
https://docs.python.org/3.6/reference/simple_stmts.html#the-global-statement

IDLE

Raymond Hettinger, “Being a Core Developer in Python”
PyBay2016
SF Python

21:45 IDLE is not the world’s greatest editor. It crashes. It has performance problems.
… Go get yourself a real editor!

42:45 A general purpose programming language can do anything.
We don’t know in advance what problem we’re solving.
Because of that, it’s very easy to invent problems…

46:30 don’t be a hypergeneralizer