計數元素

我需要能夠計算有多少字符串「O」的是在我的名單計數元素

top_board = [ 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None] 
]

後，我添加元素，如「O」和「X」，將看這樣

top_board = [ 
    ["O", None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, "O", None, None, None], 
    [None, None, None, None, None, None, None, "O", None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, "O", None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None], 
    [None, None, None, None, None, None, None, None, None] 
]

現在我需要檢查是否有在我的列表中的「O」 0的功能，如果有，然後打印東西

來源

2014-03-19 Marley Plant

你能說清楚你想要什麼嗎？請檢查top_board的任何列表中是否沒有「O」？或者每個列表是否沒有「O」？也就是'sum（[lst.count（'O'）for top_board]]'或'[sum（1 for j in i if if ==「O」）for top_board]'？ – fredtantini

def count_O(l): 
    count = 0 
    for sublist in l: 
     count += sublist.count("O") 
    return count 


if count_O(top_board) == 0: 
    #do something

來源

2014-03-19 11:50:42

試試這個：

sum(x.count("O") for x in top_board)

來源

2014-03-19 11:47:06

'top_board.count（「O」）'？ – starrify

Ehh這些錯別字 –

此外，sum（[x for x in l]）運行（不顯着但明顯）快於sum（x for x in l）'。（至少在我的機器上）：P – starrify

更新

sum([sum([1 for x in y if x == "O"]) for y in top_board])

（沒有注意到嵌套...）

來源

2014-03-19 11:48:12

cnt = sum([lst.count('O') for lst in top_board]) 
# then do something depending on cnt

來源

2014-03-19 11:49:23 starrify

if [j for i in top_board for j in i].count('O'): 
    print "O is present in the list"

來源

2014-03-19 11:55:03 Anvesh

既然你問了一個功能：

def count_O (top_board): 
    if True in ["O" in e for e in top_board]: 
     print "O found"

來源

2014-03-19 11:59:18 selllikesybok

回答

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