The Simple Syntax of F-Strings

Python 3's F-Strings: An Improved String Formatting Syntax Christopher Bailey 01:20

This lesson demonstrates the simple syntax of f-Strings. You’ll see that the syntax is similar to the one you used with str.format() but less verbose.

00:00 Now that you’ve looked at old-school string formatting, I’ll have you take a look at f-strings—the new, improved way to format strings. First I’ll show you simple syntax, then talk about arbitrary expressions, multiline f-strings, and then make speed comparisons.

00:15 f-strings are also known as formatted string literals. They have a very simple syntax. One big advantage is they are evaluated at runtime. And they are formatted using the __format__ protocol.

00:26 The basic format looks like an f at the beginning of your string, then inside curly braces, {}, you’ll have different expressions that will be evaluated at runtime.

00:36 Let me show you some examples. f-strings have a very simple syntax. If you put a couple of variables in, to build the string, inside of our curly braces, we’ll put our expressions—in this case, simply the names of these variables. And, if you’d like, you can use capital F instead of a lowercase f at the beginning of your string

01:00 and it’ll work the same. Or it’ll look like—if there are even more—just the same.

01:14 Nice, clean, simple. Next, let me tell you a little more about these expressions.

Raphael on March 13, 2019

Thank you for the lesson. I’m migrating our software from Python 2.x to Python 3.x. f-Strings are indeed nice, clean and simple as you said.

Regards, Raphael

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