python f-string example

Aimee 152 Published: 12/18/2024

python f-string example

Here's an example of using Python's f-string to format a string:

name = "John"

age = 30

country = "USA"

Using the old way with % operator

print("My name is %s, I'm %d years old and from %s." % (name, age, country))

Now using f-strings

print(f"My name is {name}, I'm {age} years old and from {country}.")

When you run this code, it will output:

My name is John, I'm 30 years old and from USA.

My name is John, I'm 30 years old and from USA.

As you can see, using f-strings makes the code cleaner and more readable. You don't have to use the % operator to format your string anymore.

F-strings are a new way of formatting strings in Python that was introduced in version 3.6. They make it easier to embed expressions inside string literals, without having to convert them to a format string first.

Here's an example of how you can use f-strings:

name = "John"

age = 30

print(f"Hello {name}, you are {age} years old.")

When you run this code, it will output:

Hello John, you are 30 years old.

F-strings work by embedding expressions inside curly braces. You can use any type of expression in an f-string, including variables, function calls, and even other strings.

Here's an example of how you can use f-strings with multiple values:

name = "John"

age = 30

country = "USA"

print(f"My name is {name}, I'm {age} years old and from {country}.")

When you run this code, it will output:

My name is John, I'm 30 years old and from USA.

As you can see, f-strings make it easy to format strings with multiple values. They also support many other features that make them more powerful than traditional string formatting.

Here's an example of how you can use f-strings with dictionaries:

person = {"name": "John", "age": 30}

print(f"My name is {person['name']}, I'm {person['age']} years old.")

When you run this code, it will output:

My name is John, I'm 30 years old.

As you can see, f-strings make it easy to format strings with dictionary values. They also support many other features that make them more powerful than traditional string formatting.

I hope this helps! Let me know if you have any questions or need further assistance.

python f-string format float

I'd be happy to respond in English and provide information on the F-string format in Python.

F-String Format in Python

Python's f-strings (formatted string literals) are a powerful feature introduced in version 3.6. They allow you to embed expressions inside string literals, using the f prefix followed by an expression in curly braces {{}}. This makes it easy to create formatted strings with placeholders for variables and expressions.

Basic Syntax

The basic syntax of f-strings is as follows:

f"{expression}"

Where expression can be a variable, a function call, or any other valid Python expression. The expression will be evaluated, and its result will be inserted into the string.

Example 1: Simple Variable Insertion

Let's say you have a variable x with value 3, and you want to create a string that says "The value of x is {x}".

x = 3

s = f"The value of x is {x}"

print(s) # Output: The value of x is 3

Example 2: Multiple Variables

You can also insert multiple variables into the same string. Let's say you have x and y with values 3 and 4, respectively.

x = 3

y = 4

s = f"x is {x}, y is {y}"

print(s) # Output: x is 3, y is 4

Example 3: Expressions

You can also evaluate expressions within the string. For example, let's say you want to calculate the area of a circle given its radius r.

import math

r = 2

s = f"The area of the circle with radius {r} is {math.pi * r ** 2}"

print(s) # Output: The area of the circle with radius 2 is 12.566370614354858

Example 4: Float Formatting

F-strings also support float formatting. Let's say you have a variable x with value 3.14159, and you want to format it as a decimal number with two digits after the decimal point.

x = 3.14159

s = f"The value of x is {x:.2f}"

print(s) # Output: The value of x is 3.14

Example 5: Float Formatting with Thousands Separator

You can also specify a thousands separator for large numbers. Let's say you have x with value 1000000, and you want to format it as a decimal number with commas as thousand separators.

x = 1000000

s = f"The value of x is {x:,}"

print(s) # Output: The value of x is 1,000,000

These are just a few examples of the power and flexibility offered by Python's f-strings. With f-strings, you can easily create formatted strings with placeholders for variables, expressions, or even functions. This feature has greatly improved Python's string formatting capabilities, making it easier to write readable and maintainable code.

I hope this helps! Let me know if you have any further questions.