blocks|key|1906962|text|(谁认为允许这样做是个好主意？)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1906963|我可以想象，原因可能是允许将来自不同类型的对象存储在类似树的结构中，这些结构在内部使用比较。|1906964|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

(And who thought it was a good idea to allow this to begin with???)

I can imagine that the reason might be to allow object from different types to be stored in tree-like structures, which use comparisons internally.

blocks|key|2263808|text|允许进行这些比较的原因是排序。Python2.x可以对包含混合类型的列表进行排序，包括字符串和整数--整数总是首先出现的。Python3.x不允许这样做，这正是您指出的原因。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2263809|Python2.x：|2263810|>>>+sorted([1,+'1'])
[1,+'1']
>>>+sorted([1,+'1',+2,+'2'])
[1,+2,+'1',+'2']|code-block|syntax|javascript|2263811|Python3.x：|2263812|>>>+sorted([1,+'1'])
Traceback+(most+recent+call+last):
++File+"<stdin>",+line+1,+in+<module>
TypeError:+unorderable+types:+str()+<+int()|2263813|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The reason why these comparisons are allowed, is sorting. Python 2.x can sort lists containing mixed types, including strings and integers -- integers always appear first. Python 3.x does not allow this, for the exact reasons you pointed out.

Python 2.x:

<pre><code>&gt;&gt;&gt; sorted([1, '1'])
[1, '1']
&gt;&gt;&gt; sorted([1, '1', 2, '2'])
[1, 2, '1', '2']
</code></pre>

Python 3.x:

<pre><code>&gt;&gt;&gt; sorted([1, '1'])
Traceback (most recent call last):
 File "&lt;stdin&gt;", line 1, in &lt;module&gt;
TypeError: unorderable types: str() &lt; int()
</code></pre>

blocks|key|2263835|text|就像亚伦说的。把它分解成你的观点：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2263836|因为它使排序能够在中途可用，否则根本就没有意义(混合列表)。一般来说，这不是一个好主意，但Python中的很多内容都是为了方便而不是严格。|ordered-list-item|2263837|按类型名称排序。这意味着同一类型组的事物在一起，它们可以在其中进行排序。它们可能应该按类型类分组，例如数字在一起，但是没有合适的类型类框架。其中可能有一些更具体的规则(可能是数字类型的规则)，我必须检查源代码。|2263838|一个是字符串，另一个是unicode。然而，他们可能有一个直接的比较操作，但是可以想象，一个不可比较的类型会在他们之间被分组，造成混乱。我不知道是否有避免这种情况的密码。|2263839|所以，这在一般情况下是没有意义的，但偶尔也会有所帮助。|2263840|from+random+import+shuffle
letters=list('abcdefgh')
ints=range(8)
both=ints%2Bletters
shuffle(ints)
shuffle(letters)
shuffle(both)
print+sorted(ints%2Bletters)
print+sorted(both)|code-block|syntax|javascript|2263841|两者都先打印ints，然后打印字母。|2263842|通常，您不希望在程序中随机混合类型，而且显然Python+3阻止了Python+2在不存在的情况下试图使其具有模糊的意义。如果您真的愿意，仍然可以按lambda+a,b:+cmp(repr(a),repr(b))+(或其他更好的)进行排序，但语言开发人员似乎认为这是不切实际的默认行为。我希望它是不同的，这给我们带来了最小的惊喜，但是在Python+2的意义上，发现问题要困难得多。|offset|length|style|CODE|2263843|entityMap^0|0|0|0|0|0|0|0|22|W|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|10|8|@]|9|@]|A|$]]|$1|E|3|F|5|D|7|11|8|@]|9|@]|A|$]]|$1|G|3|H|5|D|7|12|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|M|7|14|8|@]|9|@]|A|$N|O]]|$1|P|3|Q|5|6|7|15|8|@]|9|@]|A|$]]|$1|R|3|S|5|6|7|16|8|@$T|17|U|18|V|W]]|9|@]|A|$]]|$1|X|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|Y|$]]

As Aaron said. Breaking it up into your points:

<ol>
<li>Because it makes sort do something halfway usable where it otherwise would make no sense at all (mixed lists). It's not a good idea generally, but much in Python is designed for convenience over strictness.</li>
<li>Ordered by type name. This means things of the same type group together, where they can be sorted. They should probably be grouped by type class, such as numbers together, but there's no proper type class framework. There may be a few more specific rules in there (probably is one for numeric types), I'd have to check the source.</li>
<li>One is string and the other is unicode. They may have a direct comparison operation, however, but it's conceivable a non-comparable type would get grouped between them, causing a mess. I don't know if there's code to avoid this.</li>
</ol>

So, it doesn't make sense in the general case, but occasionally it's helpful.

<pre><code>from random import shuffle
letters=list('abcdefgh')
ints=range(8)
both=ints+letters
shuffle(ints)
shuffle(letters)
shuffle(both)
print sorted(ints+letters)
print sorted(both)
</code></pre>

Both print the ints first, then the letters. 

As a rule, you don't want to mix types randomly within a program, and apparently Python 3 prevents it where Python 2 tries to make vague sense where none exists. You could still sort by <code>lambda a,b: cmp(repr(a),repr(b))</code> (or something better) if you really want to, but it appears the language developers agreed it's impractical default behaviour. I expect it varies which gives the least surprise, but it's a lot harder to detect a problem in the Python 2 sense.

In python 3, <code>int(50)&lt;'2'</code> causes a <code>TypeError</code>, and well it should. In python 2.x, however, <code>int(50)&lt;'2'</code> returns <code>True</code> (this is also the case for other number formats, but <code>int</code> exists in both py2 and py3). My question, then, has several parts:

<ol>
<li>Why does Python 2.x (&lt; 3?) allow this behavior?</li>
<ul>
<li>(And who thought it was a good idea to allow this to begin with???)</li>
</ul></li>
<li>What does it mean that an <code>int</code> is less than a <code>str</code>?
<ul>
<li>Is it referring to <code>ord</code> / <code>chr</code>? </li>
<li>Is there some binary format which is less obvious?</li>
</ul></li>
<li>Is there a difference between <code>'5'</code> and <code>u'5'</code> in this regard?</li>
</ol>

Why is int(50)<str(5) in python 2.x?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在python 3中，int(50)<'2'会导致一个TypeError，而且它应该这样做。但是，在python2.x中，int(50)<'2'返回True (其他数字格式也是如此，但int同时存在于py2和py3中)。我的问题有几个部分：为什么Python2.x (< 3?)允许这种行为？(谁认为允许这样做是个好主意...

问为什么python2.x中的int(50)<str(5)？
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