Array rows being filled instead of individual elements

Question

The array rows are being over written, so i'm getting the last column written across the array. tilegrid[x][y]=n appears to fill the entire row. I'm calling it a row but it's the Nth item in each sub array that gets over written.

tilegrid=[['O']*7]*9
while running>0:
    my = pygetwindow.getWindowsWithTitle('HuniePop 2 - Double Date')
    if my:
        #left, top, right, bot = win32gui.GetWindowRect(my)
        #rect=(my[0].left,my[0].top,my[0].width,my[0].height)
        rect=(my[0].left,my[0].top,my[0].left+my[0].width,my[0].top+my[0].height)
        #print(rect)
        p = PIL.ImageGrab.grab(bbox=rect)
        #p = pyautogui.screenshot(region=rect)
        for y in range(0,7):
            for x in range(0,9):
                extract=p.crop(box=(gx+space*x,gy+space*y,gx+size+space*x,gy+size+space*y))
                #name="all"+str(x)+str(y)+".png"
                #extract.save(name)
                n='O'
                low=999999
                for i in tilelist:
                    out=PIL.ImageChops.difference(extract,i[0])
                    val=ImageStat.Stat(out).sum[0]
                    if val<low:
                        low=val
                        n=i[1]
                tilegrid[x][y]=n
                #print(tilegrid[x][y],end='')
                #print(tilegrid)
                print(n,end='')
            print()
        print()
        for y in range(0,7):
            for x in range(0,9):
                print(tilegrid[x][y],end='')
            print()
        print(tilegrid)
        time.sleep(10)
    else:
        print('Window not found')
        running=running-1
        time.sleep(10)

If I uncomment the line #print(tilegrid) I can see during each iteration in x the entire row gets filled.

CFPFNFSCD
DFFHSCPDX
XDHDFBXSB
NCNNXNHCF
NPNNFHHDH
SHCDSNFSP
SHCDHCBNF

DDDDDDDDD
XXXXXXXXX
BBBBBBBBB
FFFFFFFFF
HHHHHHHHH
PPPPPPPPP
FFFFFFFFF
[['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F'], ['D', 'X', 'B', 'F', 'H', 'P', 'F']]

score 0 · Answer 1 · answered Mar 20 '21 at 22:10

I've just seen someone post a related question here: For loop doesn't append info correctly into 2D array. How do I fix this? (Python)

Your first line creates 9 refferences to the same list. To see it just run this:

tilegrid=[['O']*3]*4
tilegrid[0][0]="a"
print(tilegrid)

Array rows being filled instead of individual elements

1 Answers1