在Python中奇怪的對象計數

我試圖用對象進行實驗 - 我想要一個可以計算實例數量的對象。在Python中奇怪的對象計數

我的代碼：

class Location: 
    count = 0 

    def __init__(self, column, row): 
     self.column = column 
     self.row = row 
     self.num = Location.count 
     Location.count += 1 

    def position(self): 
     print("Col: %i, Row: %i, Instance: %i" % (self.column, self.row, self.num)) 


# set up grid 
grid = [[0]*5]*5 

# Create objects in all positions 
for i in range(0, len(grid)): 
    for j in range(0, len(grid[i])): 
     grid[i][j] = Location(i, j) 
     grid[i][j].position() #prints correctly 



for i in range(0, len(grid)): 
    for j in range(0, len(grid[i])): 
     grid[i][j].position() #prints incorrectly -- WHY?!?!

爲什麼它，打印內容時電網的第二次，顯示出完全錯誤的數據？

我基本上是創建一個對象類的實例的網格。我能夠跟蹤此對象中的實例數量。

這段代碼並不適用於任何特別的東西 - 只是爲了我自己的享受和學習！

編輯**輸出編：

Col: 0, Row: 0, Instance: 0 
Col: 0, Row: 1, Instance: 1 
Col: 0, Row: 2, Instance: 2 
Col: 0, Row: 3, Instance: 3 
Col: 0, Row: 4, Instance: 4 
Col: 1, Row: 0, Instance: 5 
Col: 1, Row: 1, Instance: 6 
Col: 1, Row: 2, Instance: 7 
Col: 1, Row: 3, Instance: 8 
Col: 1, Row: 4, Instance: 9 
Col: 2, Row: 0, Instance: 10 
Col: 2, Row: 1, Instance: 11 
Col: 2, Row: 2, Instance: 12 
Col: 2, Row: 3, Instance: 13 
Col: 2, Row: 4, Instance: 14 
Col: 3, Row: 0, Instance: 15 
Col: 3, Row: 1, Instance: 16 
Col: 3, Row: 2, Instance: 17 
Col: 3, Row: 3, Instance: 18 
Col: 3, Row: 4, Instance: 19 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24 
Col: 4, Row: 0, Instance: 20 
Col: 4, Row: 1, Instance: 21 
Col: 4, Row: 2, Instance: 22 
Col: 4, Row: 3, Instance: 23 
Col: 4, Row: 4, Instance: 24

感謝

來源

2017-02-21 Mr D

從未列出的名單上應用乘法，除非你完全知道會 –

請告訴我們輸出什麼。計算機輸出不是「不正確」。你認爲它「不正確」是「不正確的」。關於它。 – pltrdy

是的 - 我接受計算機打印我告訴它打印的內容。 > _ < –

的問題是不是在你的類，但在你的網格;您正在創建五個同一個五個實例列表的副本。

而是使用列表理解：

grid = [[0]*5] for _ in range(5)]

來源

2017-02-21 11:11:28

謝謝...完美的工作！我使用了一個Python可視化工具，我可以看到它總是指向相同的列表，我無法弄清楚爲什麼。再次感謝！ –

在Python中奇怪的對象計數

回答

相關問題