f-strings in Python: Precision Decimal

Introduction

Python 3.6 introduced formatted string literals, or f-strings for short. This new way of formatting strings allows programmers to embed expressions inside string literals, using a minimal syntax. One of the features of f-strings is the ability to format decimal numbers with a certain level of precision. In this article, we'll explore how to achieve that.

Syntax

The syntax for f-strings is straightforward: just prefix the string with the letter f and use curly braces {} to include expressions inside the string. To format a decimal number using f-strings, we can use the .n syntax, where n is the number of digits we want to include after the decimal point.

Here's an example:

x = 3.14159265359
print(f"The value of pi is about {x:.2f}")

In this example, we're using an f-string to print the value of x with only two digits after the decimal point. The .2f syntax tells Python to format the number as a float with two digits after the decimal point.

Examples

Let's look at some more examples to illustrate the power of f-strings with decimal precision.

x = 0.1 + 0.1 + 0.1
print(f"The value of x is {x:.3f}")

In this example, we're using an f-string to print the value of x, which should be 0.3. However, due to the way floating-point numbers are represented in computers, we get a slightly different result. By using the .3f syntax, we're telling Python to print the value with three digits after the decimal point, which gives us a more accurate representation of the value of x.

import math
x = math.sqrt(2)
print(f"The square root of 2 is approximately {x:.4f}")

In this example, we're using an f-string to print the square root of 2 with four digits after the decimal point. The .4f syntax tells Python to format the number with four decimal places. This can be useful when we want to print the value of a mathematical expression with a certain level of precision.

Conclusion

In conclusion, f-strings with decimal precision are a powerful feature in Python that can help us print numerical values with a specific level of precision. By using the .n syntax, we can tell Python exactly how many digits we want after the decimal point. This can be useful when working with floating-point numbers or when printing the values of mathematical expressions.