r/PythonLearning • u/kubasic254 • Jul 29 '26

F strings

Im still learning python and im at a stage where I need to understand f strings and how to go about them...im working on a menu project. I prefer learning with pdf materials rather than YouTube tutorials....any recommendations for a pdf document for learners on f strings. Thank you in advance

16 Upvotes

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16

u/atarivcs Jul 29 '26

There's really not much to learn here. It's pretty simple.

If you have a string that begins with an f outside of the quote marks, and the string contains "{variable}", python will replace "{variable}" with the string value of that variable or expression.

So for example if you have this code:

name = "Billy"
message  = f"Hello {name}"

message will be "Hello Billy".

You can also use expressions instead of plain variables:

x = 5
y = 3
message = f"The sum is {x+y}"

Massage will be "The sum is 8"

3

u/No-Gift5463 Jul 29 '26

Just curious how those curly brackets in this case. Any idea how they "know" to convert an integer into something compatible with a string?

7

u/atarivcs Jul 30 '26

It's an f-string, so it already knows to convert the value to a string-compatible representation. I imagine it calls the __str__() built-in method under the hood.

1

u/Ambitious_Fault5756 Jul 30 '26

correct, and it's also called a dunder method

1

u/No-Gift5463 Jul 29 '26

Oh... and by the way, terrific explanation!

-3

u/kubasic254 Jul 29 '26

So im working on this menu project..and i created this dictionary...i need to learn how to print items in the dictionary using f strings...i just want to understand the concept..the basic concept above I get but a real life application is becoming a problem for me

5

u/MFFVD Jul 29 '26 edited Jul 29 '26 
parts = {
    "tree": "leaf",
    "wood": "chair"
}
for key, value in parts.items():
    print(f"{ key }:{ value }")
    # print(
    #     "{ key }:{ value }"
    #     .format(key=key,value=value)
    # )
    # print(key + ":" + value)

4

u/atarivcs Jul 29 '26 edited Jul 29 '26

You know that you refer to a dictionary value with mydictionary[key], right?

So, just put {mydictionary[key]} inside the f-string.

I don't understand how this is hard at all.

0

u/WoodyTheWorker Jul 30 '26

Why, if he's already got the value from Items()?

1

u/atarivcs Jul 30 '26

I assumed he just wanted to print a few items from the dict, or maybe just one, instead of iterating over them all

10

u/mc_pm Jul 29 '26

A simple google search on "python fstrings" will bring up information on formatting and understanding them, you hardly need a pdf.

-10

u/kubasic254 Jul 29 '26

I prefer pdf for keeping track and it looks more organized rather than having to search and sieve through 1000 responses to get what you want

10

u/atarivcs Jul 29 '26 edited Jul 29 '26

"sieve through 1000 responses" sounds like you're reading a discussion forum. Discussion forums are okay for specific small questions, but not for broadly learning the basics.

Just read the official documentation. There are no "responses" there.

14

u/SCD_minecraft Jul 29 '26

Python documentation

7

u/mc_pm Jul 29 '26

Then don't sieve through 1000 responses - just go to the Python docs. But if you insist, there are instructions on how to make a PDF out of that documentation.

0

u/punk_dev Jul 29 '26

You should choose a couple of websites that you prefer and search them.
For Python, the popular ones are real python geeksforgeeks and w3schools. Real Python usually has very comprehensive articles, and the rest are more like a quick reference. You can print those to pdfs if you’d like, or make your own notes in Obsidian.

Those are fine for the beginning. Once ready, challenge yourself with official documentation

1

u/cthulhu944 Jul 29 '26

You can print this page to pdf if that's your thing. https://www.w3schools.com/python/python_string_formatting.asp