how do i can i put an else statement in a list comprehension in python code example

Example 1: list comprehension if

[f(x) for x in sequence if condition]

Example 2: list comprehension for loop and if

matrix = [[1, 2], [3,4], [5,6], [7,8]]
transpose = [[row[i] for row in matrix] for i in range(2)]
print (transpose)