list comprehension, avoiding the none return on animation nodes expression I'm stuck with an issue which is actually solved in the documentation of Animation Nodes here but as I'm still learning python I can't find the error.

This expression should append elements to a list after a condition:

[filas.append(x) for x in list if x == sector_name]


But as in the docs is explained the return will be none we have to add the list created like this:

[list.append(element), list][1]


but I can't figure out how to write my expression correctly, please some help.
Lists can be joined with "+": 
So you make a new list (list comprehension) with all the x for which the condition is True and simply add it to the existing list.

filas + [x for x in list if x == sector_name]