Create .swp file manually which is compatible with nano and vim.

lock.py

import os

LOCKSIZE = 1024
lockdata = bytearray(LOCKSIZE)
file_name = 'balance.dat'
mypid = os.getppid()

def strncopy(parent_value, child_value, start):

    if start >= len(parent_value):
        parent_value.extend(bytearray(start-len(parent_value)+len(child_value)))
    
    for index in range(len(child_value)):
        parent_value[start+index] = child_value[index]

    return parent_value


lockdata[0] = 0x62
lockdata[1] = 0x30
lockdata = strncopy(lockdata, bytearray("nano 4.8", encoding='utf-8'), 2)

lockdata[24] = mypid % 256
lockdata[25] = (mypid//256) % 256
lockdata[26] = (mypid//(256*256)) % 256
lockdata[27] = mypid//(256*256*256)

lockdata = strncopy(lockdata, bytearray(os.getlogin(), encoding='utf-8'), 28)
lockdata = strncopy(lockdata, bytearray(os.uname()[1], encoding='utf-8'), 68)
lockdata = strncopy(lockdata, bytearray(file_name, encoding='utf-8'), 108)
lockdata[1007] = 0x55

lockdata = bytes(lockdata)
# print(len(lockdata))

with open(f".{file_name}.swp", "wb") as f:
    f.write(lockdata)