a.py

#!/usr/bin/env python3

import re
import sys

prog = re.compile(r"\\N(?:{[^{}]*})?")
prog2 = re.compile(r"(Dialogue: \w*,\w*:\w*:\w*.\w*,\w*:\w*:\w*.\w*,\w*,\w*,\w*,\w*,\w*,\w*,)(.*)")

for line in sys.stdin:

    if line.startswith("Dialogue"):
        mt = prog2.match(line)
        if mt and len(mt.groups()) == 2:
            a, b = mt.groups()
            sp = prog.split(b)
            if len(sp) == 2:
                print((a+sp[0]).strip(), file=sys.stderr)
                print((a+sp[1]).strip(), file=sys.stdout)
                continue

    print(line.strip(), file=sys.stderr)
    if not re.findall(r'[\u4e00-\u9fff]+', line):
        print(line.strip(), file=sys.stdout)