#!/usr/bin/env python
class User:
	def __init__(self, bag):
		''' Initialize the Computer class.
			
			@param bag: the bag with letters.
		'''
		self.__letters = bag.remove_letters()
				
	
	def get_letters(self):
		''' Return the list of Letters.
			
			@return: the list of elements.
		'''		
		return self.__letters
		
	def letters_length(self):
		''' Return the length of the list of Letters.
			
			@return: the number of elements.
		'''
		return len(self.__letters)
	
	def get_letter_at(self, index):
		''' Get the letter at the specified index of the list.
			
			@param index: the index
			@return: the Letter
		'''		
		return self.__letter[index]
	
	def add_letter(self, letter):
		''' Add a new Letter to the list of Letters.
			
			@param letter: the new Letter.
		'''
		self.__letters.append(letter)
	
		
	def add_letter_from_bag(self, bag, amount = 0):
		''' Add  new Letters to the list of Letters.
			
			@param bag: the bag which contains the Letters.
			@amount: the amount.
		'''
		new_letters = bag.remove_letters(amount)
		for letter in new_letters:
			self.add_letter(letter)
	
	
	def return_letters_to_bag(self, bag, amount = 0):
		''' Return Letters to the bag.
			
			@param bag: the bag which contains the Letters.
			@amount: the amount.
		'''
		# implementar...