Python supports object-oriented programming and has concise, readable, and easy-to-learn syntax. It is no wonder that it is one of the most popular programming languages. An integral part of Python are its built-in functions.
We've written a series of articles to help you learn and brush up on the most useful Python functions. In this article, we’ll learn about the round() function in Python and how to use it.
If you are preparing for a tech interview, check out our technical interview checklist, interview questions page, and salary negotiation e-book to get interview-ready! Also, read Python String join() Method, Python Exit commands, and Type and Isinstance In Python for more content on Python coding interview preparation.
Having trained over 10,000 software engineers, we know what it takes to crack the toughest tech interviews. Our alums consistently land offers from FAANG+ companies. The highest ever offer received by an IK alum is a whopping $1.267 Million!
At IK, you get the unique opportunity to learn from expert instructors who are hiring managers and tech leads at Google, Facebook, Apple, and other top Silicon Valley tech companies.
Want to nail your next tech interview? Sign up for our FREE Webinar.
In this article, we’ll cover:
- What Is the round() Function in Python and What Does It Do?
- The round() Function in Python: Syntax
- The round() Function in Python: Example
- FAQs on the round() Function in Python
What Is the round() Function in Python and What Does It Do?
The round function in Python rounds a number to a specific decimal place and returns a floating-point number rounded as per our specifications. It takes the following arguments:
- Any number
- The number of decimal places (optional)
The number of decimal places is set to zero by default. So the round() function returns the nearest integer to the number passed if the number is the only argument passed.
The round() Function in Python: Syntax
round(number, numberOfDigitsPostDecimal)
Here:
- number refers to the number to be rounded off.
- numberOfDigitsPostDecimal refers to the number of digits after the decimal number will be rounded off to. If you don’t provide this argument, you’ll get an integer as the result of round() applied on any float type number.
The round() Function in Python: Example
Here, we take a look at how you can use the Python function round() next time you need it:
Code
# Rounding off integers using round()
print("Round integer 33: ")
print(round(33))
# Rounding off floating point, to show that at 0.5, it rounds to the closest even number
print("Round odd and even, positive float 33.5 and 34.5: ")
print(round(33.5))
print(round(34.5))
print("Round odd and even, negative float -33.5 and -34.5: ")
print(round(-33.5))
print(round(-34.5))
# Rounding off floating point, case of less than, equal to, and more that 0.5 being rounded off
print("Round positive float 0.4, 0.5, 0.6: ")
print(round(0.4))
print(round(0.5))
print(round(0.6))
# Rounding off floating point, case of negative numbers, less than, equal to, and more that -0.5 being rounded off
print("Round negative float -0.4, -0.5, -0.6: ")
print(round(-0.4))
print(round(-0.5))
print(round(-0.6))
# Rounding off floating point <0.5, 2="" upto="" various="" places="" of="" decimal="" print("round="" 0.4="" 0,1,="" and="" decimal:="" ")="" print(round(0.4,0))="" print(round(0.4,1))="" print(round(0.4,2))="" #="" rounding="" off="" floating="" point="0.5," 0.5="" print(round(0.5,0))="" print(round(0.5,1))="" print(round(0.5,2))="">0.5, upto various places of decimal
print("Round 0.6 upto 0,1, and 2 places of decimal: ")
print(round(0.6,0))
print(round(0.6,1))
print(round(0.6,2))
Output
Round integer 33:
33
Round odd and even, positive float 33.5 and 34.5:
34
34
Round odd and even, negative float -33.5 and -34.5:
-34
-34
Round positive float 0.4, 0.5, 0.6:
0
0
1
Round negative float -0.4, -0.5, -0.6:
0
0
-1
Round 0.4 upto 0, 1, and 2 places of decimal:
0.0
0.4
0.4
Round 0.5 upto 0, 1, and 2 places of decimal:
0.0
0.5
0.5
Round 0.6 upto 0, 1, and 2 places of decimal:
1.0
0.6
0.6
Note that in the case of 0.5, the round() function rounds the number off to the nearest even number.
Found this article helpful? You can learn about more Python functions in our learn folder.
FAQs on the round() Function in Python
Q1. What does round() in Python return?
The round function in Python takes any number as an argument and returns a floating-point number rounded as per our optionally provided specifications. If no specifications are provided, it rounds to zero decimal places, giving us the nearest integer.
Q2. How do you round a float in Python 3?
You round off a float number to your desired decimal place using the built-in function round() in Python.
Q3. How do you round a number num to three decimal places in Python?
The syntax for that would look like this: round(num, 3)
Q4. In Python, the round() function rounds up or down?
The round() function can round the values up and down both depending on the situation. For <0.5, it rounds down, and for >0.5, it rounds up. For =0.5, the round() function rounds the number off to the nearest even number. So, 0.5 is rounded to zero, and so is -0.5; 33.5 and 34.5 are both rounded off to 34; -33.5 -34.5 are both rounded off to -34, and so on.
Q5. By default, round() in Python rounds to how many decimal places?
By default, if not mentioned, the round() method rounds the given number to zero decimal places.
Ready to Nail Your Next Coding Interview?
Whether you’re a coding engineer gunning for a software developer or software engineer role, a tech lead, or you’re targeting management positions at top companies, IK offers courses specifically designed for your needs to help you with your technical interview preparation!
If you’re looking for guidance and help with getting started, sign up for our FREE webinar. As pioneers in the field of technical interview preparation, we have trained thousands of software engineers to crack the toughest coding interviews and land jobs at their dream companies, such as Google, Facebook, Apple, Netflix, Amazon, and more!
.png)
