python one line statement for loop with if else

Question

Is it possible to write this logic in one line statement?

B = []
for book in books:
    if book not in B:
         B.append(book)

I have tried this but it's false:

B = [book if book not in B for book in books]

Is there a way to reference the variable inside itself?

@C.LECLERC Sure, if you insist on having a `list`. If any iterable will do, keeping it as a `set` is just fine as well. — deceze, Oct 06 '16 at 10:56

score -5 · Answer 1 · answered Oct 06 '16 at 10:36

-5

B=[book for book in books if  not book in B]

should do the trick

answered Oct 06 '16 at 10:36

JMat

I havetried this code but the books of B are duplicated .. – pietà Oct 06 '16 at 10:40
2

@pietà Because `B` is only being defined after this comprehension is done. This will actually fail with a `NameError: name 'B' is not defined`. If you still have a `B = []` defined previously you obviously circumvent that error… – deceze Oct 06 '16 at 10:43

1 Answers1