Comments can be used to explain Python code.
Comments can be used to make the code more readable.
Comments can be used to prevent execution when testing code.
Creating a Comment
Comments starts with a #
, and Python will ignore them:
Comments can be placed at the end of a line, and Python will ignore the rest of the line:
A comment does not have to be text that explains the code, it can also be used to prevent Python from executing code:
Multi Line Comments
Python does not really have a syntax for multi line comments.
To add a multiline comment you could insert a #
for each line:
Example
#This is a comment
#written in
#more than just one line
print["Hello, World!"]
Try it Yourself »
Or, not quite as intended, you can use a multiline string.
Since Python will ignore string literals that are not assigned to a variable, you can add a multiline string [triple quotes] in your code, and place your comment inside it:
Example
"""
This is a comment
written in
more than just one line
"""
print["Hello, World!"]
Try it Yourself »
As long as the string is not assigned to a variable, Python will read the code, but then ignore it, and you have made a multiline comment.
Test Yourself With Exercises
Exercise:
Comments in Python are written with a special character, which one?
Start the Exercise
Commenting is an integral part of every programming language. With comments, you get a better
understanding of your own code, make it more readable, and can help team members understand how it works. Comments are ignored by compilers and interpreters, so they don’t run. Apart from making your code more readable, comments can also help while you're debugging – if you have two lines of code, you can comment out one to prevent it from running.
Just like other programming languages, Python supports comments.
The problem is that Python doesn't have a built-in mechanism for multi-line comments.
So in this article, I won't just show you how to make single-line comments in Python – I'll also show you the workaround for making multi-line comments.
To make single-line comments in Python, prepend each line with a hash [#
].
# print["Hello world"]
print["Hello campers"]
Output:
Hello campers
As you can see, the commented line wasn't printed in the output.
Unlike other programming languages such as JavaScript, Java, and C++ which use /*...*/
for multi-line comments, there's no
built-in mechanism for multi-line comments in Python.
To comment out multiple lines in Python, you can prepend each line with a hash [#
].
# print["Hello world"]
# print["Hello universe"]
# print["Hello everyone"]
print["Hello campers"]
Output:
Hello campers
With this approach, you're technically making multiple single-line comments.
The real workaround for making multi-line comments in Python is by using docstrings.
If you use a docstring to comment out multiple line of code in Python, that block of code will be ignored, and only the lines outside the docstring will run.
"""
This is a multi-line comment with docstrings
print["Hello world"]
print["Hello universe"]
print["Hello everyone"]
"""
print["Hello campers"]
Output:
Hello campers
NB: One thing to note is that while using doctsrings for commenting, indentation still matters. If you use 4 spaces [or a tab] for indentation, you will get an indentation error.
For example, this will work:
def addNumbers[num1, num2, num3]:
"""
A function that returns the sum of
3 numbers
"""
return num1 + num2 + num3
print[addNumbers[2, 3, 4]]
# Output: 9
But this won't work:
def addNumbers[num1, num2, num3]:
"""
A function that returns the sum of
3 numbers
"""
return num1 + num2 + num3
print[addNumbers[2, 3, 4]]
So your IDE will throw the error "IndentationError: expected an indented block
".
Conclusion
Since there's no built-in support for multi-line comments in Python, this article demonstrates how you can use docstrings as a workaround.
Still, you should generally stick to using regular Python comments using a hash [#
], even if you have to use it for multiple lines. This is because docstrings are meant for documentation, and not for commenting out code.
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Thank you for reading.
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