python - python monty < python 等为什么？

Question

>>> "Monty" < "Python" 
True 
>>> "Z" < "a" 
True 
>>> "Monty" < "Montague" 
False 

这有什么规矩？是字母的数量还是什么？谢谢

Answer 1

它是按字典顺序排序的。所以“a”<“b”。

如果您使用该ord()函数，您可以看到“Z”的值低于“a”

>>> ord('Z')
90
>>> ord('a')
97

Answer 2

Python 字符串、元组和列表使用Lexicographical order进行比较。

元组示例：

>>> (1,2) < (2,1)
True
>>> (1,2) < (1,2,-5)
True

想法很简单：逐个元素比较（对于字符串，逐个字符），直到有差异或一个更短。

Answer 3

Be careful not to confuse this order with the locale sensitive collation sequence. For example:

>>> import locale
>>> locale.strcoll("Z","a")
-1
>>> "Z" < "a"
True

Probably what you expect, locale.strcoll returns -1 if the first string is less than the second, +1 if the first string is greater than the second (0 if they are equal).

But:

>>> locale.setlocale(locale.LC_ALL,"")
'English_United Kingdom.1252'
>>> locale.strcoll("Z","a")
1
>>> "Z" < "a"
True

The locale can change the collation sequence, but (here) not with ordinary comparisons. The English collation sequence goes aAbBcC...xXyYzZ (applies to other "en" locales). For example:

>>> ml=["a","b","c","A","B","C"]
>>> sorted(ml)
['A', 'B', 'C', 'a', 'b', 'c']
>>> sorted(ml,key=locale.strxfrm)
['a', 'A', 'b', 'B', 'c', 'C']
>>> 

With non-ASCII characters, consider:

>>> locale.strcoll("é","f")
-1
>>> "é" < "f"
False

Answer 4

按照字母在 ASCII 范围内定义的顺序进行词法排序，因此：

A ... Za ... z

这就是为什么'Z' < 'a'是真的。

比较两个字符串时，比较每个字符，如果一个大于另一个，则字符串更大，如果相等，则移动到下一个字符。如果到达其中一个字符串的末尾，而另一个字符串仍然有字符，则最长的字符串更大，否则它们相等。