Which of the following is not a built-in method? Group of answer choices .sort() .insert() .count() .xfill()

To determine which of the following is not a built-in method, we will analyze each option:

1. .sort(): This is a built-in list method in Python that sorts the elements of a list in place.
2. .insert(): This is also a built-in list method in Python that inserts an element at a specified position in the list.
3. .count(): This method counts the number of occurrences of a specific element in a list and is a built-in method in Python.
4. .xfill(): This is not a standard built-in method in Python. It appears to be a typographical error or a misunderstanding, as there is no built-in method called .xfill().

Conclusion

The method that is not built-in is .xfill().