Changing Variables within Variables?

[volcano63]

How do I make variables within variables modifiable?

y = '1'
x = 'hello'+y
y = '2'

If I print <x>, it will only give me  'hello1' not 'hello2'. 

Is there an easy way to make <y> modifiable within <x>?

You are confusing string concatenation with list copy modification
When you do something like 

x = [1, 2]
y = x
x[0] = 2

then y[0] will become 2 too, because both x and y point to the same list in memory. Assignment in Python does create a new alias (reference, pointer) to right hand operator.

With x = 'hello'+y you create a new temporary string object than ends with value of the string in y and creates reference x to that object; that new object does not contain reference to y

Of course, you can always try  to override string object to simulate that behavior