Why can define not be used to define variables?

Question

I'm trying to use the define function to create a series of variables. Each variable will be what the user inputs and will then be used in later code.

The crux of the problem is shown below. I assumed I could define var in fnctn as input, and then substitute var with new variables (word1, word2, etc) when the function is recalled.

But I get "NameError: name 'word1' is not defined" whenever I attempt to run it. If you can insert a string or an integer into a recalled defined function, why not a variable? And what could a workaround for this be?

def fnctn(var):
var = input("enter a word: ")

fnctn(word1)
fnctn(word2)
etc.

Answer 1

First, You can substitute value in function. Not variable.
Second, You can reassign variable to new value.
So, in your code, word1 & word2 must be defined before calling function.

word1 = 'Hello'
word2 = 'World'
When you call fnctn function, this happen --> fnctn(var = word1 (or) word2)

And you reassign that var to new value which is returned by input function.
So, value contained in your 'word' variable will be never used.