如何替换字符串中的第二次出现？

Question

我想用“狗”代替“正在下雨的猫和猫”中第二次出现的“猫”。

text = "Its raining cats and cats"
a = text.replace(str(text.endswith("cats")), "dogs")
print(a)

Answer 1

def replace_ending(sentence, old, new):
    sentence_array = sentence.split()
    if sentence_array[-1]== old:
        sentence  = sentence.rsplit(" ",1)[0];
        new_sentence = sentence + " " + new
        return new_sentence
    return sentence

print(replace_ending("It's raining cats and cats", "cats", "dogs"))

Answer 2

尝试一下：

text = "Its raining cats and cats".split(' ') # splits it at space
text[text.index('cats', text.index('cats')+1)] = 'dogs' # find where cat occurs after the first occurrence (if you have 3 instead of two and want to replace the third, this won't work) and replaces it
text = " ".join(text) # rejoins text using space

Answer 3

从查找第一次出现的位置开始，然后在该位置之后进行替换。还要为str.replace设置一个 count ，以确保仅第二次出现被替换。

text = "It's raining cats and cats"
old, new = 'cats', 'dogs'
offset = text.index(old) + 1
a = text[:offset] + text[offset:].replace(old, new, 1)
print(a)  # -> "It's raining cats and dogs"

P.s。我还把它变成了一个超级通用的库函数，稍后我可能会在GitHub上发布它。我想请按照这个答案进行更新。