Python Float Rounding Tutorial

This tutorial will guide you through the process of rounding floating-point numbers in Python using the built-in round function. Rounding numbers is useful to improve readability and precision in your output.

Getting Started

Suppose you have a set of float numbers and you want to add them together, but the result has too many decimals. Let's explore how to round the result to achieve a cleaner and more readable output.

Example

# List of float numbers
float_numbers = [23.456, 78.912, 163.234, 0.789]

# Summing up the float numbers
result = sum(float_numbers)

# Display the unrounded result
print("Unrounded Result:", result)

Round to Two Decimal Places

To round the result to two decimal places, you can use the round function:

# Round to two decimal places
rounded_result = round(result, 2)

# Display the rounded result
print("Rounded to Two Decimal Places:", rounded_result)

This will output a much cleaner result, such as 266.39.

Round to Different Decimal Places

You can experiment with rounding to different decimal places by changing the argument passed to the round function:

# Rounding to one decimal place
print("Rounded to One Decimal Place:", round(result, 1))

# Rounding to zero decimal places (nearest whole number)
print("Rounded to Zero Decimal Places:", round(result, 0))

# Rounding to minus one decimal places (rounding the whole numbers)
print("Rounded to Minus One Decimal Places:", round(result, -1))

# Rounding to minus two decimal places (rounding to the nearest hundred)
print("Rounded to Minus Two Decimal Places:", round(result, -2))

Feel free to adjust the decimal places to observe how the rounding behavior changes.

Conclusion

Using the round function in Python is a simple and effective way to control the precision of your floating-point numbers. Experiment with different decimal places to find the level of precision that best suits your needs.

Happy coding! 🐍