old_contents: from builtins import input 
  
  #!/usr/bin/env Python3
  # Python 2 & 3 
  
  ''' Python program to fill storage device(s)  with either zeroes(0s), or a random pattern of zeroes(0s) and ones (1s). '''
  
  # Import os functions
  import os
  
  def user_float(): 
      ''' Prompt user for input, accepting only valid input.'''
      while True: 
          try: 
              return float(input('How many times would you like to wipe this device?: '))
          except ValueError: 
              print('Bad value, try again.')
  
  def osCheck():
  	''' Check if OS is UNIX-like. '''
  	if os.name =='posix': 
  		print('Let there be wipe!') 
  	else: 
  		print('NOT POSIX-compliant, can not proceed.')
  
  osCheck()
  
new_contents: from builtins import input 
  
  #!/usr/bin/env Python3
  # Python 2 & 3 
  
  ''' Python program to fill storage device(s)  with either zeroes(0s), or a random pattern of zeroes(0s) and ones (1s). '''
  
  # Import os functions
  import os
  
  def userFloat(): 
      '''Prompt user for input, accepting only valid input.'''
      while True: 
          try: 
              return float(input('How many times would you like to wipe this device?: '))
          except ValueError: 
              print('Bad value, try again.')
  
  def osCheck():
  	'''Check if OS is UNIX-like.'''
  	if os.name =='posix': 
          print('Proceed')
      else: 
          print('Halt')
  
  def zeroDisk(): 
      '''Fill disk with zeros (0s).'''
      return os.system('dd if=/dev/zero')
  
  def randomDisk(): 
      '''Fill disk with random sequence of zeros (0s) and (1s).'''
      return os.system('dd if=/dev/random')
  
subject: add pseudo functions