Python Class and Instance Methods (@classmethod), Static Methods (@staticmethod) Principles and Usage Analysis

class Tool(object):
  # Define class attributes using assignment statements to record the number of all instantiated tool objects
  count = 0
  # @classmethod Defines a class method. The first argument is cls (cls is used to access class attributes and class methods, not instance attributes/methods).
  @classmethod
  def show_tool_count(cls):
    # Cannot access instance properties
    print("Number of tool objects %d" % ) # cls.class attribute name Access to class attributes (in class methods)
  def __init__(self, name):
     = name # Instance properties
    # Class name. Class Attribute Name Access to class attributes (in instance methods)
     += 1
# Instantiate tool objects
tool1 = Tool("The Axe.")  # tool1.__class__ attribute points to the class object. tool1.__class__.count instance object accesses class attribute
tool2 = Tool("Hammer.")
# Class name. Class Methods Calling Class Methods
Tool.show_tool_count()

class Dog(object):
  # @staticmethod Defines static methods; class attributes/methods and instance attributes/methods cannot be accessed inside static methods. No default parameters need to be passed.
  # Static methods in Python do the same thing as regular functions defined outside a class, except that they indicate that the function is for use by that class only.
  @staticmethod
  def run():
    # Cannot access instance attributes/class attributes
    print("The puppies are going to run...")
# Class name. Static method name Invoke static method without creating object (can also be invoked by instance object).
()