change_file_by_date.py

import os
import time

start_timestamp = 1550587841

for serial in os.listdir('.'):
    for fn in os.listdir(serial):
        ctime = os.stat(os.path.join(serial, fn)).st_ctime
        if ctime > start_timestamp:
            date_in_filename = fn.split('_')[0]
            date_in_file_ctime = time.strftime('%Y-%m-%d', time.localtime(ctime))

            if date_in_filename != date_in_file_ctime:
                profer_name = fn.replace(date_in_filename, date_in_file_ctime)
                # fix error
                src = os.path.join(serial, fn)
                dst = os.path.join(serial, profer_name)
                os.rename(src, dst)