正则表达式但仅在子字符串中

Question

我找不到正则表达式的解决方案，该正则表达式仅在字符串的特定范围内寻找模式，但仅在字符串的特定范围内

我想找到$ $，但前提是它位于字符串的5-7位置，并且这两个之间的哪个字符都没有关系
例子

xxxx$x$xxxxx would match
xx$x$xxxxxxx would not

Answer 1

import re

should = "xxxx$x$xxxxx would match"
shouldnt = "xx$x$xxxxxxx would not"

pattern = r'^.{4}\$.\$.+'

re.match(pattern, should)
re.match(pattern, shouldnt)

给予

match
None

https://regex101.com/r/RLHrZb/1