python key=lambda 理解和 C# 等效
我自己记录了有关“key=lambda”功能的信息，并找到了有关其使用的很好的参考：
http://www.daniweb.com/software-development/python/threads/376964
感谢它，我开始了解以下代码“应该”做什么：
def _min_hull_pt_pair(hulls):
"""Returns the hull, point index pair that is minimal."""
h, p = 0, 0
for i in xrange(len(hulls)):
j = min(xrange(len(hulls[i])), key=lambda j: hulls[i][j])
if hulls[i][j] < hulls[h][p]:
h, p = i, j
return (h, p)
但是我有一个以下语法的问题：
j = min(xrange(len(hulls[i])), key=lambda j: hulls[i][j])
我的疑问，作为一个Python学徒，尽管学得很快：
1-我是否需要像调用堆栈一样回溯以了解我检索的“类型”或更简单的“值”[我][j]？ （我读到 python 使用“鸭子打字”，如果我没记错的话，这可以解释这种需求）。
2- key=lambda j 基本上“检索”了 hulls 的 [i][j] 元素，不是吗？但这是否意味着 hulls[i][j] 是整数类型，因为“for”迭代使用 for 的 xrange 调用“min”？
3-可选：是否有 c# 与 python 的 min 等效或相当？
提前致谢。
I have documented myself regarding the 'key=lambda' functionality, and have found a good reference on its use:
http://www.daniweb.com/software-development/python/threads/376964
thanks to which I came to understand what the following code is 'supposed' to do:
def _min_hull_pt_pair(hulls):
"""Returns the hull, point index pair that is minimal."""
h, p = 0, 0
for i in xrange(len(hulls)):
j = min(xrange(len(hulls[i])), key=lambda j: hulls[i][j])
if hulls[i][j] < hulls[h][p]:
h, p = i, j
return (h, p)
however I have a problem with the following syntax:
j = min(xrange(len(hulls[i])), key=lambda j: hulls[i][j])
My doubts, being a python apprentice albeit learning fast:
1- do I need to trace back the calls stack-like to understand what 'type' or more simply 'value' I get retrieving hulls[i][j]? (I read that python uses the 'duck typing', which would explain this need, if I'm not mistaken).
2- key=lambda j basically 'retrieves' the [i][j] element of hulls, doesn't it? But does this mean that hulls[i][j] is an integer type, since the 'for' iteration calls 'min' with the for's xrange?
3- optional: is there a c# equivalent or comparable to python's min?
Thanks in advance.
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是的。特别是，hulls[i][j] 可以是任何类型或任何值，具体取决于运行时发生的情况。例如，所有 hulls 都可以是整数，但您可以设置
hulls[i][j]='foo'。是的，那里的 lambda 返回 hulls 中第 i 行的第 j 个元素。 hulls[i][j] 可以是任何类似的东西，例如
min('a','b') is 'a'Yes. In particular, hulls[i][j] could be any type or any value depending on what happened at runtime. e.g. all of hulls could be integers, but you can set
hulls[i][j]='foo'.Yes, the lambda there returns the jth element of the ith row in hulls. hulls[i][j] could be any comparable thing e.g.
min('a','b') is 'a'