Python for-in loop preceded by a variable

Question

foo = [x for x in bar if x.occupants > 1]

After googling and searching on here, couldn\'t figure out what this does. Maybe I wasn\'t searching

Answer 1

The way this should work as far as I can tell is it checks to see if the list "bar" is empty (0) or consists of a singleton (1) via x.occupants where x is a defined item within the list bar and may have the characteristic of occupants. So foo gets called, moves through the list and then returns all items that pass the check condition which is x.occupant.

In a language like Java, you'd build a class called "x" where 'x' objects are then assigned to an array or similar. X would have a Field called "occupants" and each index would be checked with the x.occupants method which would return the number that is assigned to occupant. If that method returned greater than 1 (We assume an int here as a partial occupant would be odd.) the foo method (being called on the array or similar in question.) would then return an array or similar as defined in the foo method for this container array or what have you. The elements of the returned array would be the 'x' objects in the first array thingie that fit the criteria of "Greater than 1".

Python has built-in methods via list comprehension to deal with this in a much more succinct and vastly simplified way. Rather than implementing two full classes and several methods, I write that one line of code.