The old way

Do you remember when you have learned about strings? You probably have defined a function hello_world similar to the code below:

def hello_world():
print("Hello, world!")

And then you progressed to write a function that could greet not the whole world but a particular person. Something similar to the definition below:

def hello_world(name):
print("Hello, " + name + "!")

Or even better-formatted version below:

def hello_world(name):
print("Hello, {}!".format(name))

F-strings offer another, even simpler, and even more readable version of the function above. Below we redefine the function using f-strings.

def hello_world(name):
print(f"Hello, {name}!")

As you can see the string is proceeded by the letter f and the variable name that needs to be inserted in the string is enclosed by curly brackets { }. No need for the .format() function anymore.