By Lenin Mishra
A lot of times you will have difficulties figuring out what is going on in a Python program. Even if you are the author of the program, you might have difficulties navigating your own code after a period of time.
Comments are very useful in such scenarios as they describe the intent and functionality of your code.
In Python, you can write comments in 3 different ways.
Single line Comments
You can use the hash symbol
# to write single-line comments in Python.
Everything that comes after the hash symbol
# is ignored by the Python interpreter.
# printing Hello World print("Hello World!") x = 10 y = 20 # Tuple Swap x, y = y, x str1 = "Pylenin loves Python" # Return the first and last character print(str1 + str1[-1])
Python doesn’t provide any unique way for multi-line comments. However, any string can be used as a comment in Python, as long as it is not asigned to a variable. Python interpreter ignores such strings.
"This line will be ignored" print("Pylenin loves Python") """ Bigger comments can be written over multiple lines. This is a multi-line comment. """ print("Pylenin loves Python")
Run the above code and you will see that no errors are raised by Python.
Docstrings are not similar to comments. However, they have a similar purpose.
Docstring is short for documentation string.
Python docstrings are the string literals that appear right after the definition of a function, method, class, or module. They are used to provide a meaningful description about the above mentioned objects.
Use triple quotes to write docstrings.
def addition(x,y): """Takes x and y and returns their sum""" return x+y print(addition.__doc__)
Takes x and y and returns their sum
You can also use Docstrings in a Python class.
class Person: """Stores the name, age and country of a person""" def __init__(self, name, age, country): self.name = name self.age = age self.country = country print(Person.__doc__)
Stores the name, age and country of a person
Where to use comments and Docstrings?
Use comments where you believe the way your code written is not too obvious to understand for a programmer.
Use docstrings to provide information about various objects like functions and classes in your code.