max_index=len(words)-1 can someone explain that part for me?

Answer 1

max_index = len(words)-1

let's split up this statement

'max_index' is the variable u declare
in that variable u are calling a default function 'len()'
the purpose of len function is to return the length of the passed argument
for example
len('hello')
would return 5 since 'hello' contains five characters.
so now coming back to question.
the len() has a variable as an argument.
this variable might be declared but u missed it let's take it as

words='sample'

len(words) is 6 and a '-1' is given at end
'max_index' now stores the answer '5'

Hope you got it

Answer 2

laPerro answer well but in short the variable max_index will store 5