Python Find minimum object using special comparator

问题

So I got my question answered on how to find the minimum value, but what if I want the minimum object? Can we similarly simplify this code?

        min = 9999
        minChild = None
        for child in currentRoot.children:              
            if child.score < min:
                min = child.score
                minChild = child
            recurseWriteBook(child, depth+1)

回答1:

Use built-in function min(iterable[, key]):

>>> class Foo(object):
...     def __init__(self, value):
...         self.value = value
...
>>>
>>> l = [Foo(2), Foo(1), Foo(3)]
>>>
>>>
>>> min_foo = min(l, key = lambda x: x.value)
>>>
>>> min_foo.value
1

You tell it which key/attribute to use to compare objects.

回答2:

You know your types (list/tuples) and how to adjust them, so you can use technique like this:

list_min = [1,2,3,4] # list to demonstrate

m = lambda mn,lst: filter(lambda x: x <mn,lst) # get the minimum out of list

minimum = 3 # test value
print m(minimum,list_min)

回答3:

I used the answer I selected plus the answer from my other question to use this:

minChild = min(currentRoot.children, key = lambda child: child.score)

来源：https://stackoverflow.com/questions/37980286/python-find-minimum-object-using-special-comparator