How to swap string and save - python-3.x

Question

I am having problems saving the file i modifyed basicly i need to replace in original file string called DTC_5814_removing and switch_data and save it as a seperate file how would i do that, so here is what program basicly does, it opens eeprom file, then searches for a string between two strings and groups it, then counts the data and by that given data searches for other string that is between two strings and modyfies data,basicly the code works i have a question how is the best way to save that as a seperate file, filesave function currently has no functin
here is the code:
import re
#checking the structures counting
file = open ("eeprom", "rb") .read().hex()
filesave = open("eepromMOD", "wb")
DTC_data = re.search("ffff30(.*)100077", file)
DTC_data_final = print (DTC_data.group(1))
#finds string between two strings in 2nd line of eeprom file
switch_data = re.search("010607(.*)313132", file)
switch_data_final = print (switch_data.group(1))
#finds string betwenn two strings in 3rd line of eeprom file
DTC_data_lenght = (len(DTC_data.group(1)))
#lenght of the whole DTC_data group
DTC_312D = re.search("ffff30(.*)312d", file)
DTC_3036 = re.search("ffff30(.*)3036", file)
DTC_5814 = re.search("ffff30(.*)5814", file)
#searching for DTC 312D
DTC_312D_lenght = (len(DTC_312D.group(1))+4)
DTC_312D_lenght_start =(len(DTC_312D.group(1)))
DTC_3036_lenght = (len(DTC_3036.group(1))+4)
DTC_3036_lenght_start =(len(DTC_3036.group(1)))
DTC_5814_lenght = (len(DTC_5814.group(1))+4)
DTC_5814_lenght_start =(len(DTC_5814.group(1)))
#confirming the lenght of the DTC table
if DTC_312D_lenght <= DTC_data_lenght and DTC_312D_lenght%4==0 :
#If dtc lenght shorter than whole table and devidable by 4
print("Starting DTC removal")
#Printing for good count
switch_data_lenght = (len(switch_data.group(1)))
#Counting switch data table
DTC_312D_removing = switch_data.group(1)[:DTC_312D_lenght_start] + "0000" + switch_data.group(1)[DTC_312D_lenght:]
#Read from data group (data[:define start] + "mod to wish value" + data[define end]
print(DTC_312D_removing)
else:
print("DTC non existant or incorrect")
if DTC_3036_lenght <= DTC_data_lenght and DTC_3036_lenght%4==0 :
#If dtc lenght shorter than whole table and devidable by 4
print("Starting DTC removal")
#Printing for good count
switch_data_lenght = (len(switch_data.group(1)))
#Counting switch data table
DTC_3036_removing = DTC_312D_removing[:DTC_3036_lenght_start] + "0000" + switch_data.group(1)[DTC_3036_lenght:]
#Read from data group (data[:define start] + "mod to wish value" + data[define end]
print(DTC_3036_removing)
else:
print("DTC non existant or incorrect")
if DTC_5814_lenght <= DTC_data_lenght and DTC_5814_lenght%4==0 :
#If dtc lenght shorter than whole table and devidable by 4
print("Starting DTC removal")
#Printing for good count
switch_data_lenght = (len(switch_data.group(1)))
#Counting switch data table
DTC_5814_removing = DTC_3036_removing[:DTC_5814_lenght_start] + "0000" + switch_data.group(1)[DTC_5814_lenght:]
#Read from data group (data[:define start] + "mod to wish value" + data[define end]
print(DTC_5814_removing)
else:
print("DTC non existant or incorrect")

Answer 1

Solved with
File_W = file.replace(switch_data.group(1), DTC_5814_removing)
File_WH = binascii.unhexlify(File_W)
filesave.write(File_WH)
filesave.close()