List comprehension with if statement

Question

I want to compare 2 iterables and print the items which appear in both iterables.

>>> a = ('q', 'r') 

>>> b = ('q') 

# Iterate over a. If y not in b, print y. 

# I want to see ['r'] printed. 

>>> print([ y if y not in b for y in a]) 

^

But it gives me an invalid syntax error where the ^ has been placed. What is wrong about this lambda function?

Answer 1

The code that you have written is in wrong order wrong. The if should be after the for (unless it is in an if-else ternary operator)

[y for y in a if y not in b]