将列表列表与列表进行比较以找到相似的数字

Question

这是我尝试过的：

my_tickets = [ [ 7, 17, 37, 19, 23, 43],
           [ 7, 2, 13, 41, 31, 43],
           [ 2, 5, 7, 11, 13, 17],
           [13, 17, 37, 19, 23, 43] ]

def lotto_matches(xs, my_tickets):
   xi = 0 # could be used to pick specific things from lists
   yi = 0 # could be used to pick specific things from lists
   result = []
   for i in my_tickets: # List of lists
      for x in xs: # Picks
         if my_tickets[i] == xs[x]: #Not sure what my if statement is suppose to be
            result.append() # I don't know what goes in the parenthesis
    print (result)
    return (result)

lotto_matches([42,4,7,11,1,13], my_tickets)

我正在尝试编写一个函数，该函数接受一张票和一张平局的列表，并返回一个列表，说明每张票上的正确选择数。

它应该返回[1,2,3,1]，但我的输出完全错误。

我该怎么做？

Answer 1

除非您的彩票抽奖有更多的球，否则创建集合的开销几乎不值得。

def lotto_matches(xs, my_tickets):
    xs = set(xs) # optional - may not be any faster if xs is a small list
    return [sum(x in xs for x in t) for t in my_tickets]

Answer 2

如果您需要一个衬里：

output = [len(list(set(a_list) & set(draw))) for a_list in my_tickets]

Answer 3

您可以像这样使用map 和intersection：

def lotto_matches(pick, my_tickets):
    result = map(lambda x: len(set(x).intersection(pick)), my_tickets)
    return result

print lotto_matches([42,4,7,11,1,13], my_tickets)

pick 是您的比赛门票。

如果您使用的是 Python 3，map 返回的迭代器可能不是您想要的，因此您需要

return list(result)

Answer 4

1. 您没有在代码中正确累积结果。每次迭代都应该开始计数，并在最后追加结果。

2. for i in my_tickets 迭代票证本身，而不是它们的索引。

这里是固定代码：

def lotto_matches(xs, my_tickets):
    results = []
    for ticket in my_tickets:
        result = 0
        for number in ticket:
            for x in xs: 
                if number == x: 
                    result += 1
        results.append(result)
    return result

---

现在，通过扁平化你的循环，这可以变得更漂亮：

1. 这个 if 语句

   if number == x: 
       result += 1
   

   可以利用True被解释为1的事实：

   result += (number==x)
   

2. 这个

   result = 0
   for number in ticket:
       for x in xs: 
           result += (number==x)
   

   是使用嵌套循环计算的和，可以转换成这个

   result = sum(number==x for number in ticket for x in xs)
   

   这是检查ticket 中存在的所有x 值，可以使用in 进行简化（同样的，x in ticket 将在x 存在时返回True (1)在ticket):

   result = sum(x in ticket for x in xs)
   

   也就是说，如果xs 中的x 出现在ticket 中，我们希望在总和中加一。

3. 现在，我们有了这个

   results = []
   for ticket in my_tickets:
       result = sum(x in ticket for x in xs)
       results.append(result)
   

   相当于

   results = [sum(x in ticket for x in xs) for ticket in my_tickets]
   

4. 因此，您的整个代码可以是单行代码：

   def lotto_matches(xs, my_tickets):
       return [sum(x in ticket for x in xs) for ticket in my_tickets]