Python 正则表达式替换 substring 和值

Question

我想从字符串中替换子字符串{以某种格式}。 如果没有找到 substring ，则 append 一些字符串到原始字符串。

这可能有点令人困惑，所以让我试着举个例子。 我想用AGE XXX替换AGE/age {digits} 。 如果没有找到， append NO AGE FOUND 。

例如，假设我们有一个字符串

He is in old age. At AGE 51, something something. At age 12 he bla bla.

这应该替换为

He is in old age. At AGE XXX, something something. At AGE XXX he bla bla.

另一个例子：

He is in old age. Something something bla bla.

将替换为：

He is in old age. Something something bla bla. NO AGE FOUND

这可能根本没有意义，只是试图创建一个类似于我的情况的示例。

Answer 1

您可以使用re.subn ：

import re

def redact(text):
    redacted, n_found = re.subn(r"(age|AGE)\s+\d+", "age XXX", text)
    return redacted if n_found else redacted + " NO AGE FOUND"

print(redact("He is in old age.  At AGE 51, something something.  At age 12 he bla bla."))
# He is in old age.  At age XXX, something something.  At age XXX he bla bla.

print(redact("He is in old age.  Something something bla bla."))
# He is in old age.  Something something bla bla. NO AGE FOUND

具体来说， re.subn返回一个包含新字符串和替换次数的元组。