Skip to main content

What is Duck Typing




I had originally answered this on Quora and thought that I should also make it available here in my blog for the readers who do not follow Quora (by the way it's a great site and you should follow that 😎).

Duck typing is a concept that says that the “type” of the object is a matter of concern only at runtime and you don’t need to to explicitly mention the type of the object before you perform any kind of operation on that object.

The following example can help in understanding this concept -
  1. def calc(a,b):
  2. return a+b
Now, Python says that for the above function I don’t need to be concerned about the “type” of the objects ‘a’ & ‘b’ and that the type will be taken care of during runtime as long as the objects support the ‘+’ . So, keeping this in mind the above function will work for any “type” of object which supports the operator + i.e. it will return valid values for a string, list or Integer. When I pass the following “types” of object then the function should work-
  1. calc(1,2) → will return 1+2 = 3
  2. calc('hello','world') --> will return hello world
  3. calc([1],[2]) --> will return [1,2]
What we got in the above results?
  • In the first example of 1,2 since python interpreter recognizes these objects as type integer and since the operator + is valid for integers so the function calc returns a valid output of “type”integer 3. Here while passing the objects 1,2 to the function calc we are not defining that these objects are “type” integer as due to duck typing concept in python, the objects 1,2 are interpreted as integers and hence the function calc must return an output of type integer.
  • In the second example we did not explicitly mentioned anywhere that the objects hello & world are of “type” string, but duck typing concept comes into play and the interpreter recognizes these objects as strings during runtime and when these are passed to the function calc then the output should be a valid string ‘hello world’.
  • In the third example also duck typing can be noticed as the “type” of [1] & [2] is interpreted by python as lists and so the operator + should concatenate (which is a valid operation for lists) these two strings into a bigger string.
More about operators here

Now that you know what duck typing is and that it’s one of the powers of Python you can get started in learning the other features of Python and start exploring this programming language. If you found this post helpful and you have any suggestion to improve my blog then do post your comments below.

If you wanna get started in learning Python then why not get started with the python basics chapter. Check out this link to access the Python Basic Chapter for free.
If you want to download a copy of the chapter then purchase the chapter by clicking on the following link.

Additionally you can also bug me on Quora. You can also find me on Twitter or Facebook. So, why wait go ahead and start exploring.

Comments

Post a Comment

Popular posts from this blog

How To Install Tensorflow On Windows

Why I am writing this tutorial ? Recently I have started learning machine learning specifically DeepLearning for one of my pet projects, and during this quest of mine I wanted to learn TensorFlow library which is developed by Google. Learning is one thing but first I needed to install the library, but there was this problem which I faced during the installation. I am using Anaconda as my package manager and trying to install the Tensorflow library on my work computer which is behind a proxy, installing directly from the anaconda cloud while behind a proxy always displayed a proxy error. How did I resolve the issue? Well this is exactly what I am going to write down in the below tutorial. The Steps To Follow Before we get all cosy with this short tutorial on Tensorflow installation, let me tell you that this tutorial is on the assumption that you have already installed Anaconda on your machine and you know at least a few basic things or two about python. If y...
Post a Comment
Read more

While Loop in python : How to become a Python Jedi - Beginners Python Programming Tutorial - Part 6

Welcome back friends to another post on TheCodingProject and we are back with the sixth chapter of the Beginner Python programming tutorial - How to become a python Jedi. This time we are going to learn how to use while loop in python. The While Loop statement? In Python Programming, There are 3 types of loops → While loop For loop Nested loops Now to get into some action→ Let’s consider that two groups of aliens have landed on earth  out of these two one of the group is good & the other are the bad guys. The govt. Has given you the task of designing a system that takes in input from different eyewitnesses & then classify that whether the aliens that these eyewitnesses encounter are the good guys or bad guys. Copy & paste the above code in your editor and run this code. What do you get ? When the input is Autobots it matches the condition aliens == "Autobots" & it enters the loop to prints the statement pointed b...
Post a Comment
Read more

For Loop in python 3 : How to become a Python Jedi - Beginners Python Programming Tutorial - Part 7

I am back again with another part in the beginner python programming tutorial series. We will continue with "Loops" but this time we are going to learn how to use for loop in python 3.  Difference between For loop and While Loop A "For Loop" and "While Loop" have a common connection that both are looping statement, but major difference is that unlike while loop, a for loop gets executed a specified number of times. We can break down the For loop into the following components(Refer to the for loop flow chart below). for keyword variable name call to the range function colon operator clause or block of code Hovering over the flow-chart The above flow-chart is..well horrible I know, but I make my own drawings because I can't afford an artist. So, bear with me. In the above flowchart is a very basicy, laymanish representation of a for loop. The decision box contains the  For  statement along-with it's sou...
Post a Comment
Read more