从regex中避开完整路径的一部分，同时保留它的一部分

\/path\/to\/(file\.txt)

import re

path = "/path/to/file.txt"
pattern = r"\/path\/to\/(file\.txt)"
match = re.search(pattern, path)
if match:
    filename = match.group(1)
    print(filename)  # 输出: file.txt

import java.util.regex.Matcher;
import java.util.regex.Pattern;

String path = "/path/to/file.txt";
String pattern = "\\/path\\/to\\/(file\\.txt)";
Pattern regex = Pattern.compile(pattern);
Matcher matcher = regex.matcher(path);
if (matcher.find()) {
    String filename = matcher.group(1);
    System.out.println(filename);  // 输出: file.txt
}