How do I get the sum of specific attributes from objects in a list?-CodePudding

I have a list of "Tile" objects with attributes defined as such:

class Tile:

    def __init__(self, water, soil):
        self.water = water
        self.soil = soil
    

Lake = Tile(20, 0)
Dirt = Tile(0, 10)
Tree = Tile(-5, -5)

These objects fill the following list:

environment = [Dirt, Tree, Lake, Dirt, Dirt]

Is there a way for me to get the total sum of .water and .soil for all objects in the list?

CodePudding user response：

Add up the waters:

sum(tile.water
    for tile in environment)

Similarly for soil values:

sum(tile.soil
    for tile in environment)

It's unclear if you wanted them combined:

sum(tile.water   tile.soil
    for tile in environment)

CodePudding user response：

For your question, one of the first things that comes to mind is to loop through your collection and get the soil and water values like so:

soil = water = 0
for tile in environment:
    soil  = tile.soil
    water  = tile.water

If you want to have both combined, simply modify the code by removing a variable and adding both tile.soil and tile.water to the combined sum.

There are more advanced ways to do it, using the sum function like in J_H's answer, or even using map and operator.attrgetter shenanigans, but it's not really worth it at your level of Python proficiency seems to be.

Hope this helped :)