如何获得二维数组中的精灵？

Question

I want to replace array string 'a' with sprite, thus I display images :

arr = ['a','a','a','a']
for i in arr:
    if i == 'p':
        arr[i] = Alien("Alien.png", (20,40))
print(arr[1])                  
# give  <Alien sprite(in 0 groups)>

Next I tried to figure out how to get access to each image to give a motion for every image after replace in array, but code doesn't work as I expected. I don't know how to operate each image apart?

for j in arr:
    if j == '<Alien sprite(in 0 groups)>':
        j.move(9,11)

Answer 1

In the second loop, I don't think j == .. would work in you favour. When you print the object in the python prompt it would print <PawnBlue sprite(in 0 groups)> , however checking the string equality as you have wouldn't be right way to check if that particular array index contains an image or not.

I see in your previous loop you are inserting instances of the Alien class into the array. Assuming those are the images that you are talking about, in the second loop change the if statement to if type(j) == Alien : This should work.