What one line code algorithm in python 3 will give such result?

The test question is in the form of a fill in the blanks and this question shows part of the code and requires me to provide the code the programmer must have entered to give the result printed in a single line statement.

a = [1, 2, 3, 4, 5, 6, 2, 4, 1, 7, 8]
#[fill in the blank in one line]
print(a)
#[1, 2, 3, 4, 5, 6 ,7 8]

The result is the list shown rearranged with no duplicates in it.