Python 两个元组的最大值

Python文档指出，当使用多个参数调用时，max（）返回最大的参数

>>> a = (1, 1, 1, 9)
>>> b = (4, 5, 6)
>>> max(a, b)
(4, 5, 6)

---

在这种情况下，是什么定义了元组的大小？元组a有更多的元素（四个对三个），并且它的最大值（9）大于在b（6）中可以找到的最大值，因此根据任何标准，我都希望它是返回的。max（）如何比较元组？

它们一次比较一个元素，就像其他序列一样。如果将其与字符串比较，则（可能）最容易理解：

>>> (1, 2, 3) > (1, 2, 4)
False
>>> (2, 2, 3) > (1, 2, 4)
True
>>> 'abc' > 'abd'
False
>>> 'bbc' > 'abd'
True

---

元组和所有其他序列一样是按字典顺序排列的：两个元组的顺序由元组不同的第一个位置决定。引述自：

元组和列表是使用 相应的元素

您的两个元组在第一个位置不同，因为4>1，所以

>>> (4, 5, 6) > (1, 1, 1, 9)
True

---

它从左到右比较元组的每个元素，直到找到一个大于另一个。然后返回这个元组。比如说

>>> a = (2,0,0,0)
>>> b= (1,1,1,1)
>>> max(a,b)
(2, 0, 0, 0)

>>> b = (2,1,1,1)
>>> max(a,b)
(2, 1, 1, 1)

---

在一个元组中发现大于另一个元组中相应元素的元素后，剩余值对返回的元组没有影响。

使用<进行比较大致相当于：

def compare(a,b):
    print ""
    print "testing %s < %s" %(str(a),str(b))
    for ai,bi in zip(a,b):
        print "comparing elements",ai,bi
        if ai < bi:
            return True
        if bi < ai:
            return False
    if len(a)<len(b):
        return True
    return False

test_cases = [tuple([1]),(1,2),(1,1),(1,1,1),(None,None,None),tuple([None]),(99,99)]

print "running tests"
for a in test_cases:
    for b in test_cases:
        assert(compare(a,b) == (a<b))
"""
>>>
running tests

testing (1,) < (1,)
comparing elements 1 1

testing (1,) < (1, 2)
comparing elements 1 1

testing (1,) < (1, 1)
comparing elements 1 1

testing (1,) < (1, 1, 1)
comparing elements 1 1

testing (1,) < (None, None, None)
comparing elements 1 None

testing (1,) < (None,)
comparing elements 1 None

testing (1,) < (99, 99)
comparing elements 1 99

testing (1, 2) < (1,)
comparing elements 1 1

testing (1, 2) < (1, 2)
comparing elements 1 1
comparing elements 2 2

testing (1, 2) < (1, 1)
comparing elements 1 1
comparing elements 2 1

testing (1, 2) < (1, 1, 1)
comparing elements 1 1
comparing elements 2 1

testing (1, 2) < (None, None, None)
comparing elements 1 None

testing (1, 2) < (None,)
comparing elements 1 None

testing (1, 2) < (99, 99)
comparing elements 1 99

testing (1, 1) < (1,)
comparing elements 1 1

testing (1, 1) < (1, 2)
comparing elements 1 1
comparing elements 1 2

testing (1, 1) < (1, 1)
comparing elements 1 1
comparing elements 1 1

testing (1, 1) < (1, 1, 1)
comparing elements 1 1
comparing elements 1 1

testing (1, 1) < (None, None, None)
comparing elements 1 None

testing (1, 1) < (None,)
comparing elements 1 None

testing (1, 1) < (99, 99)
comparing elements 1 99

testing (1, 1, 1) < (1,)
comparing elements 1 1

testing (1, 1, 1) < (1, 2)
comparing elements 1 1
comparing elements 1 2

testing (1, 1, 1) < (1, 1)
comparing elements 1 1
comparing elements 1 1

testing (1, 1, 1) < (1, 1, 1)
comparing elements 1 1
comparing elements 1 1
comparing elements 1 1

testing (1, 1, 1) < (None, None, None)
comparing elements 1 None

testing (1, 1, 1) < (None,)
comparing elements 1 None

testing (1, 1, 1) < (99, 99)
comparing elements 1 99

testing (None, None, None) < (1,)
comparing elements None 1

testing (None, None, None) < (1, 2)
comparing elements None 1

testing (None, None, None) < (1, 1)
comparing elements None 1

testing (None, None, None) < (1, 1, 1)
comparing elements None 1

testing (None, None, None) < (None, None, None)
comparing elements None None
comparing elements None None
comparing elements None None

testing (None, None, None) < (None,)
comparing elements None None

testing (None, None, None) < (99, 99)
comparing elements None 99

testing (None,) < (1,)
comparing elements None 1

testing (None,) < (1, 2)
comparing elements None 1

testing (None,) < (1, 1)
comparing elements None 1

testing (None,) < (1, 1, 1)
comparing elements None 1

testing (None,) < (None, None, None)
comparing elements None None

testing (None,) < (None,)
comparing elements None None

testing (None,) < (99, 99)
comparing elements None 99

testing (99, 99) < (1,)
comparing elements 99 1

testing (99, 99) < (1, 2)
comparing elements 99 1

testing (99, 99) < (1, 1)
comparing elements 99 1

testing (99, 99) < (1, 1, 1)
comparing elements 99 1

testing (99, 99) < (None, None, None)
comparing elements 99 None

testing (99, 99) < (None,)
comparing elements 99 None

testing (99, 99) < (99, 99)
comparing elements 99 99
comparing elements 99 99"""

def比较（a，b）：
打印“”
打印“测试%s<%s%”（str（a）、str（b））
对于ai，zip中的bi（a，b）：
打印“比较元素”，ai，bi
如果ai如果len（a）我也通过反复试验得出了相同的结论，但似乎在我看的任何地方都没有记录，你知道它可能在哪里吗？不，我很惊讶max（）的文档是多么的模糊。如果你想要最长的元组，请使用
max（a，b，key=len）
。对于其中数字最大的元组，使用
max（a，b，key=max）
是否在某处记录了类型间比较？我正在寻找一个解释，解释为什么“python”>[130，129]等于True，或者为什么[1，2，3]>999也返回True。不同类型的值的顺序是任意的，因此不应该依赖它。看我给你的推荐信。还有一句话：“否则，不同类型的对象总是比较不相等，并且顺序一致但任意。”另请参见。