Python - How to find if character is the last character in a string?

How do I efficiently check if a character when inside a for loop is in the last position of a string?

Like:

string = "daffyduck'd"

I would have done this through

for char in string:
  if char == string[-1]:
    break

This however prematurely ends whenever there is a char that matches the last element, so that does not work. I am dealing with pairs of chars, so when inside a for loop, i am doing a current_index and current_index + 1 operation, so without knowing the last element, I will get a string index out of bound error.