替换所有连续重复值的出现

Question

我有一个重复连续昏迷的字符串，我想在昏迷之间插入一个字符，例如零。当我运行re.sub它返回的是：

re.sub(r",,", ",0," , "a,,,,,,,,,,,,,a",)
'a,0,,0,,0,,0,,0,,0,,a'

我想要的结果是所有的替换，例如：

'a,0,0,0,0,0,0,0,0,0,0,0,0,a'

我理解为什么会发生这种情况，模式中存在重叠，但我不知道如何修复它。

Answer 1

您可以使用前瞻匹配逗号后跟另一个逗号，并将匹配替换为",0"，例如：

>>> re.sub(r",(?=,)", ",0", "a,,,,,,,,,,,,,a")
'a,0,0,0,0,0,0,0,0,0,0,0,0,a'

或者没有正则表达式：

>>> ",".join(x or "0" for x in "a,,,,,,,,,,,,,a".split(","))
'a,0,0,0,0,0,0,0,0,0,0,0,0,a'

Answer 2

这实现了预期的结果：

In [1]: re.sub(r",,", ",0,0" , "a,,,,,,,,,,,,,a",)
Out[1]: 'a,0,0,0,0,0,0,0,0,0,0,0,0,a'