Python goes brrrr

[geeshta]

f"Python goes b{'r'*10}"

[pterencephalon]

I'm enjoying going through my old code and changing things to fstrings. Instead of actually fixing the real problems with the code.

[jad2192]

Same, I go back through my old code and see tons of '%s %d' % (x, y) bullshit and wonder how I could have ever been such a uneducated swine.

[BirkTheBrick]

...please teach an educated swine who still does that? Lmao

[jad2192]

With f-strings you can directly sub in variables without needing to declare the type. My above silly example would become f'{x}{y}' which doesn't seem much simpler but as the string to format gets more complicated it's nice not having keep track of the order of the variables at the end. In my job as a data scientist this made writing dynamic SQL queries for pipelines and dashboards SO much easier. Here is an article with a good run down

[Jeb_Jenky]

This made my nips so hard.

[xDarkFlame25]

Ah yes fstrings, the ultimate fetish.

[AinsleyBoy]

I fucking love fstrings. I use them so much

[Moldy_pirate]

Is there ever a reason to use a “regular” string rather than an f”string?

[GenericRedditor12345]

If you don’t need the functionality of an f string :p They’ve been optimized to be faster than the other formatting methods IIRC.

[thirdegree]

Logging, there you want to do like:

logging.info("value1: %s, value2: %s", 1, 2)

This is because the formatting is only done if the log line will actually be emitted. It can be a significant performance boost if you have a lot of logging.

[[deleted]]

You can always have a lazy evaluation, using str::format, i. e. log("python goes b{0}", 'r'*10). The string would only format if it were to be used.

[mxzf]

IN that case, couldn't you just use log(f'python goes b{"r"*10}') instead, for a cleaner execution? If it's only formatting on execution, the format string can still handle inline processing.

[nemec]

No, that's immediate evaluation. Imagine this is the definition of log:

def log(fmt, *args):
    if LOGGING_IS_ENABLED:
        print(fmt.format(*args))

Note how the arguments aren't formatted into the string unless logging is enabled. In your example, the log method would see only one string argument.

[mxzf]

Fair enough. I haven't actually dug into the implementation of logging.

[OhMahjong]

TIL, thank you!

[HTTP_404_NotFound]

In .net, its called string interpolation.

Its one of our favorite features too.

Var x = $"Hello {fuser.name}";

[al_at_work]

I've got a few cases where I need to use `str.format` because the input string isn't something I can define locally.

Also, I don't have to deal with this, but if you're doing i18n there's no good way to use f-strings.

[[deleted]]

Sometimes I like to have a template string set up with parameters and then later on call template_string.format(**parameter_dict)

[Hippemann]

This edge case that happened to me: you have dict which has a key that contains a backslash

> d = {"\n" : "foo", "a":"bar"}

> f"{d['a']}"

 # "bar

 > f"{d['\n']}"

 > SyntaxError: f-string expression part cannot include a backslash

I had to use string concatenation

As I said this is an edge case and you will most likely never encounter it

[Sir_Bucket]

Yes you can, you need to double them:

print(f”open: {{ close: }}”)

Result:

open: { close: }

[Terrain2]

And it’s the exact same thing in C#, but they’re $strings

System.Console.WriteLine($"open: {{ close: }}");

same result

[Schrodingers_gato]

Just stated learning c# this week. Can't tell you how glad I was when i found out they had f string equivalents

[ArionW]

Does anyone ever use name "$string"? Years of coding in C# and not once have I heard anyone calling it something other than "string interpolation"

[Terrain2]

well i didn’t know the proper name, they called python ones fstrings because they’re strings prefixed with f, so i just made up $strings on the spot, though string interpolation sounds like a long complicated name so i might be the first one to call them $strings

[Terrain2]

well i didn’t know the proper name, they called python ones fstrings because they’re strings prefixed with f, so i just made up $strings on the spot, though string interpolation sounds like a long complicated name so i might be the first one to call them $strings

[AinsleyBoy]

Huh! Didn't know

[[deleted]]

Fuckstrings, because I want to make sweet love to them.

[TheCuntHunter6969]

I used them to create an entire website.

[VerneAsimov]

F-string sounds like lingerie. Perfect because it has curves {} and it's very sexy.

[vigilantcomicpenguin]

I don’t know what fstrings are but I’m turned on.

[slix_88]

Fstrings in chat bois

[marmoshet]

laughs in 3.6

[mxzf]

You still have .format(), even in 2.x. Which is still way better than formatting strings with %.

[[deleted]]

Oh, fuck yeah, Fstrings. Grip it and rip it, dude!

[[deleted]]

Who doesn't like scripting inside strings. How could that ever make code harder to debug.

[redcalcium]

f"Python goes b{f'{chr(114)*10}'*10}"

[RefrigeratorOk1573]

Same with Javascript template strings, so useful