old_contents: #! /usr/bin/python
  
  """
  Parsing eo sources.
  
  Bytes:
  >>> eo = EoParser("65 6F 20 6C 61 6E 67")
  >>> eo.parse()
  'eo lang'
  """
  
  from StringIO import StringIO
  import argparse
  import os
  
  
  class Byte(object):
  
  	def __init__(self, char, infile):
  		self.value = char + infile.read(1)
  
  	def __radd__(self, string):
  		return string + chr(int(self.value, 16))
  
  
  class EoParser(object):
  
  	def __init__(self, infile):
  		if type(infile) == str:
  			self.infile = StringIO(infile)
  		else:
  			self.infile = infile
  		self.infile.seek(0, os.SEEK_END)
  		self.length = self.infile.tell()
  		self.infile.seek(0)
  
  	def parse(self):
  		result = str()
  		while self.infile.tell() < self.length:
  			char = self.infile.read(1)
  			if char in "0123456789ABCDEF":
  				byte = Byte(char, self.infile)
  				result += byte
  		return result
  
  
  if __name__ == "__main__":
  	parser = argparse.ArgumentParser()
  	parser.add_argument("infile", nargs="?", type=argparse.FileType("r"))
  	args = parser.parse_args()
  
new_contents: #! /usr/bin/python
  
  """
  Parsing eo sources.
  
  Bytes:
  >>> eo = EoParser("65 6F 20 6C 61 6E 67")
  >>> eo.parse()
  'eo lang'
  
  Strings:
  >>> eo = EoParser(' "string in eo lang" ')
  >>> eo.parse()
  'string in eo lang'
  """
  
  from StringIO import StringIO
  import argparse
  import os
  
  
  class Byte(object):
  
  	def __init__(self, char, infile):
  		self.value = char + infile.read(1)
  
  	def __radd__(self, string):
  		return string + chr(int(self.value, 16))
  
  
  class String(object):
  
  	def __init__(self, infile):
  		self.value = str()
  		char = infile.read(1)
  		while char != '"':
  			self.value += char
  			char = infile.read(1)
  
  	def __radd__(self, string):
  		return string + self.value
  
  
  class EoParser(object):
  
  	def __init__(self, infile):
  		if type(infile) == str:
  			self.infile = StringIO(infile)
  		else:
  			self.infile = infile
  		self.infile.seek(0, os.SEEK_END)
  		self.length = self.infile.tell()
  		self.infile.seek(0)
  
  	def parse(self):
  		result = str()
  		while self.infile.tell() < self.length:
  			char = self.infile.read(1)
  			if char in "0123456789ABCDEF":
  				byte = Byte(char, self.infile)
  				result += byte
  			elif char == '"':
  				string = String(self.infile)
  				result += string
  		return result
  
  
  if __name__ == "__main__":
  	parser = argparse.ArgumentParser()
  	parser.add_argument("infile", nargs="?", type=argparse.FileType("r"))
  	args = parser.parse_args()
  
subject: Create string data type.