如何在字符串中反转位置？

Question

我有这段代码：

a = "I'll buy paper,pen and beg"
print a[::-1]

输出：     geb dna nep，repap yub ll'I

但我希望输出如下：     g'eb dna nep r，epap yub llI

我该怎么做？

Answer 1

取反向字符串并构建一个仅包含字母字符的生成器。然后使用它作为未来字母字符替换的来源：

s = "I'll buy paper,pen and beg"
rev = (ch for ch in reversed(s) if ch.isalpha())
new = ''.join(next(rev) if ch.isalpha() else ch for ch in s)
# g'eb dna nepre,pap yub llI

Answer 2

也许是这样的：

targets = ".,'"
a = "I'll buy paper,pen and beg"
punct = [ (i, c) for i, c in enumerate (a) if c in targets]
nopunct = [c for c in a if c not in targets][::-1]
for i, c in punct: nopunct.insert (i, c)
b = ''.join (nopunct)
print (a)
print (b)

打印

g'eb dna nepre,pap yub llI
I'll buy paper,pen and beg

或者将目标更改为仅打印.,

geb dna neprep,ap yub ll'I
I'll buy paper,pen and beg