Replace empty lists with tuples

Question

Given a list of tuples, the following code removes the empty lists and prints out the remaining elements:

tuples=[[(16, 178)], [], [(46, 183)], [(15, 55)], [(42, 79)], [(54, 192)], [], [(2, 86)], []]

res = [ele for ele in tuples if ele != []]
print(res)

I now want to replace the empty lists with the tuple [(0,0)]. However, this line gives me an 'invalid syntax' error:

res = [ele=[(0,0)] for ele in tuples if ele != []]

Answer 1

You need a conditional expression in the comprehension:

res = [ele if ele else [(0,0)] for ele in tuples]

You could also just use or:

res = [ele or [(0,0)] for ele in tuples ]