new_contents: #!/usr/bin/env python3
  
  from sys import argv
  from random import randint
  
  chars = ["a", "b", "c", "d", "\n"]
  
  with open(argv[1], mode="w") as f:
      for i in range(10000*1000):
          print(chars[randint(0, 4)], end="", file=f)
  
subject: add gen_data.py