#  Animals.py   Copyright (c) Kari Laitinen

#  http://www.naturalprogramming.com

#  2006-04-21  File created.
#  2022-12-18  Converted to Python 3.

#  The Animal class in this program contains a constructor, i.e., __init__()
#  method, that accepts two types of actual parameters (arguments).

#  In Python classes there can be only one constructor because
#  Python methods cannot be overloaded in the same way as, for example,
#  Java methods.

class  Animal :

   def __init__( self, given_parameter  ) :

      if isinstance( given_parameter, str ) :

         #  The given parameter is a string. We suppose that a new
         #  Animal object with the given species name is being constructed.

         self.species_name      =  given_parameter
         self.stomach_contents  =  ""

      elif isinstance( given_parameter, Animal ) :

         #  A reference to an Animal object was given as an actual parameter.
         #  The new Animal object will be a copy of the given Animal object.

         self.species_name      =  given_parameter.species_name
         self.stomach_contents  =  given_parameter.stomach_contents

      else :

         print( "\n Unacceptable object was given to Animal constructor." )


   def feed( self, food_for_this_animal ) :

      self.stomach_contents  =  \
          self.stomach_contents  +  food_for_this_animal  +  ", " 

   def make_speak( self ) :

      print(  "\n Hello, I am a "  +  self.species_name  +  "."  \
            + "\n I have eaten: "  +  self.stomach_contents  )


#  The main program begins here.

cat_object  =  Animal( "cat" )
dog_object  =  Animal( "vegetarian dog" )

cat_object.feed( "fish" )
cat_object.feed( "chicken" )

dog_object.feed( "salad" )
dog_object.feed( "potatoes" )

another_cat  =  Animal( cat_object )

another_cat.feed( "milk" )

cat_object.make_speak()
dog_object.make_speak()
another_cat.make_speak()