Polymorphism

Author: Shikha-code36

07.Polymorphism/polymorphism-1.py

@@ -0,0 +1,48 @@
+#polymorphism-1.py
+
+# Polymorphism means having the same interface/attributes in different
+# classes.
+
+# Polymorphism is the characteristic of being able to assign
+# a different meaning or usage in different contexts.
+# A not-so-clear/clean example is, different classes can have
+# the same function name.
+
+# Here, the class Dog and Cat has the same method named 'show_affection'
+# Even if they are same, both does different actions in the instance.
+#
+# Since the order of the lookup is
+# 'instance' -> 'class' -> 'parent class', even if the
+# 'class' and 'parent class' has functions with the same name,
+# the instance will only pick up the first hit,
+# ie.. from the 'class' and won't go to the parent class.
+
+
+class Animal(object):
+    def __init__(self, name):
+        self.name = name
+
+    def eat(self, food):
+        print("{0} eats {1}".format(self.name, food))
+
+
+class Dog(Animal):
+    def show_affection(self):
+        print("{0} wags tail".format(self.name))
+
+
+class Cat(Animal):
+    def show_affection(self):
+        print("{0} purrs".format(self.name))
+
+
+for a in (Dog("Tuffy"), Cat("Mona"), Cat("Lucy"), Dog("Tommy")):
+    a.show_affection()
+
+'''
+O/P-
+Tuffy wags tail
+Mona purrs
+Lucy purrs
+Tommy wags tail
+'''

07.Polymorphism/polymorphism-2.py

@@ -0,0 +1,32 @@
+#polymorphism-2.py
+
+# Another example for Polymorphism are the several inbuilt
+# functions in Python. Take for example, the builtin function
+# called 'len'.
+
+# 'len' is available for almost all types, such as strings,
+# ints, floats, dictionaries, lists, tuples etc..
+# When len is called on a type, it actually calls the inbuilts
+# private function 'len' on that type or __len__
+
+# Every object type that supports 'len' will have a private
+# 'len' function inbuilt.
+
+# Hence, for example, a list type already has a 'len()'
+# function inbuilt in the Python code, and when you run the
+# len() function on the data type, it checks if the len
+# private function is available for that type or not.
+# If it is available, it runs that.
+
+text = ["Hello", "Hola", "helo"]
+print("text",len(text))
+
+print("hello",len("Hello"))
+print("char",len({"a": 1, "b": 2, "c": 3}))
+
+'''
+O/P-
+text 3
+hello 5
+char 3
+'''

README.md

@@ -139,4 +139,13 @@ Encapsulation involves the bundling of data members and functions inside a singl
 
 [Detailed Explanation](06.Encapsulation)
 
+------------
+------------
+#### 07. Polymorphism
+
+The literal meaning of polymorphism is the condition of occurrence in different forms.
+Polymorphism in python defines methods in the child class that have the same name as the methods in the parent class. In inheritance, the child class inherits the methods from the parent class. Also, it is possible to modify a method in a child class that it has inherited from the parent class.
+
+[Detailed Explanation](07.Polymorphism)
+
 ------------