class Foo:
  cls_attr = "Class attribute"
  
  def __init__(self, arg1, arg2):
    self.attr1 = arg1 # Instance attribute
    self.attr2 = arg2
    
  @classmethod  
  def method_1(cls):
    # Class method has an access to
    # class attributes
    print(cls.cls_attr)
    return "class method"
    
  @staticmethod  
  def method_2():
    # print(cls.cls_attr) # NameError: name 'cls' is not defined
    return "static method"


def main():
  print(Foo.method_1()) # Class attribute
                        # class method
  print(Foo.method_2()) # static method
  
  f = Foo(1, "a")
  
  print("---")          # ---
  
  print(f.method_1())   # Class attribute
                        # class method
  print(f.method_2())   # static method
  

if __name__ == '__main__':
  main()