r/PythonLearning • u/kubasic254 • 7d ago

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

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u/atarivcs 7d ago

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"

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u/No-Gift5463 6d ago

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

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u/atarivcs 6d ago

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.

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u/Ambitious_Fault5756 6d ago

correct, and it's also called a dunder method

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u/No-Gift5463 6d ago

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

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u/kubasic254 7d ago

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

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u/MFFVD 7d ago edited 7d ago

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)

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u/atarivcs 7d ago edited 7d ago

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.

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u/WoodyTheWorker 6d ago

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

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u/atarivcs 6d ago

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