如何在字符串中进行条件字符替换 [英] How to do conditional character replacement within a string

问题描述

我在Python中有一个unicode字符串，基本上需要逐个字符地进行遍历，并根据规则列表替换某些特定字符串。这样的规则是，如果 a a 会更改为ö >在 n 之后。另外，如果连续有两个元音字符，它们将被一个元音字符和：代替。因此，如果我有字符串 natarook ，什么是获取nötaro：k ？如果重要的话，使用Python 2.6和CherryPy 3.1。

I have a unicode string in Python and basically need to go through, character by character and replace certain ones based on a list of rules. One such rule is that a is changed to ö if a is after n. Also, if there are two vowel characters in a row, they get replaced by one vowel character and :. So if I have the string "natarook", what is the easiest and most efficient way of getting "nötaro:k"? Using Python 2.6 and CherryPy 3.1 if that matters.

编辑：连续两个元音的意思是相同的元音（oo，aa，ii）

edit: two vowels in a row does mean the same vowels (oo, aa, ii)

推荐答案

# -*- coding: utf-8 -*-

def subpairs(s, prefix, suffix):
    def sub(i, sentinal=object()):
        r = prefix.get(s[i:i+2], sentinal)
        if r is not sentinal: return r

        r = suffix.get(s[i-1:i+1], sentinal)
        if r is not sentinal: return r
        return s[i]

    s = '\0'+s+'\0'
    return ''.join(sub(i) for i in xrange(1,len(s)))

vowels = [(v+v, u':') for v in 'aeiou']

prefix = {}
suffix = {'na':u'ö'}
suffix.update(vowels)
print subpairs('natarook', prefix, suffix)
# prints: nötaro:k

prefix = {'na':u'ö'}
suffix = dict(vowels)
print subpairs('natarook', prefix, suffix)
# prints: öataro:k

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