Python 2 maketrans() 函数不适用于 Unicode："the arguments are different lengths" 实际上是

Question

[Python 2] SUB = string.maketrans("0123456789","₀₁₂₃₄₅₆₇₈₉")

此代码产生错误：

ValueError: maketrans arguments must have same length

我不确定为什么会出现这种情况，因为字符串的长度相同。我唯一的想法是下标文本长度与标准大小的字符有些不同，但我不知道如何解决这个问题。

Answer 1

不对，参数长度不一样：

>>> len("0123456789")
10
>>> len("₀₁₂₃₄₅₆₇₈₉")
30

您正在尝试传入编码数据；我在这里使用了 UTF-8，其中每个数字都编码为 3 个字节。

您不能使用 str.translate() 将 ASCII 字节映射到 UTF-8 字节序列。将您的字符串解码为 unicode 并使用略有不同的 unicode.translate() 方法；它需要一个字典代替：

nummap = {ord(c): ord(t) for c, t in zip(u"0123456789", u"₀₁₂₃₄₅₆₇₈₉")}

这将创建一个映射 Unicode 代码点（整数）的字典，然后您可以在 Unicode 字符串上使用它：

>>> nummap = {ord(c): ord(t) for c, t in zip(u"0123456789", u"₀₁₂₃₄₅₆₇₈₉")}
>>> u'99 bottles of beer on the wall'.translate(nummap)
u'\u2089\u2089 bottles of beer on the wall'
>>> print u'99 bottles of beer on the wall'.translate(nummap)
₉₉ bottles of beer on the wall

如果您愿意，您可以再次将输出编码为 UTF-8。

来自method documentation：

For Unicode objects, the translate() method does not accept the optional deletechars argument. Instead, it returns a copy of the s where all characters have been mapped through the given translation table which must be a mapping of Unicode ordinals to Unicode ordinals, Unicode strings or None. Unmapped characters are left untouched. Characters mapped to None are deleted.

Python 2 maketrans() 函数不适用于 Unicode："the arguments are different lengths" 实际上是

Python 2 maketrans() function doesn't work with Unicode: "the arguments are different lengths" when they actually are

python

string

unicode

translate

python-2.x