5 Useful F-String Tricks In Python

Here are my top 5 most useful f-string formatting tricks that I use everyday in Python.

▶ Follow me on Instagram:

[chyldstudios]

the "=" trick in the f-string is fire.

[Zenivo]

About the fourth trick: the f in ".2f" tells it to format as float. You can also do for example ".2e"" which will format the number in scientific format.

[andymitchell]

I've been using python for about 10 years, and f strings extensively, but never knew that last tip! Game changer!

[sunwukong]

Ever since I learned f-strings...I love them.

[_Loki__Odinson_]

This is the first time I have seen someone specify datatype for variables in python, and I honestly loved it.
Great tips btw.

[BohumirZamecnik]

Very nice. Another useful is formatting float as percent: f"{foo:.2%}".

[TheJaguar]

Didn't know about the date/time and equals formatting. Looks like the first one forwards to strftime. Makes things so much more concise and readable.

[rolandsz]

Great video! I missed the bonus tip where you explain that format string calls __format__ on the object being formatted, so you can do your own formatting, like this:

class MyData:
def __init__(self, a: int, b: int, c: int):
self.a = a
self.b = b
self.c = c

def __format__(self, spec):
if spec[0] not in self.__dict__:
sep = spec[0]
l = list(spec[1:])
else:
sep = ', '
l = list(spec)

return for key in l)


my_var = MyData(a=1, b=2, c=3)
assert f"{my_var:cba}" == "3, 2, 1"
assert f"{my_var:-abc}" == "1-2-3"

[enriqueDFTL]

I never use anything other than f-strings when printing and these tips are great. Going to use them!

[im_a_surfingdoggo]

Thank you, this went STRAIGHT into my current project. Commas in numbers was one of the next things I was going to look up.

[TheMcSebi]

Great video! Didn't know about the datetime and debug print ones. Definitely going to use them in the future, though.

[quekki]

i love f strings
also this is like the 3rd time i come across the = specifier but i keep forgetting its existence and type in the whole thing

[krzysiekkrzysiek]

This kind of tips are awesone. We need more 👍

[SergioYT]

"Simple y bello como un anillo", como diría Neruda; pero además, muy funcional. ¡Muchas gracias!

[mad_vegan]

To use scientific notation with integers, you can either do int(2e9) or 2*10**9.

[UndyingEDM]

For those who didn't know, the last one is called self-documenting expression and was released in Python 3.8

[KinkyJalepeno]

This series of vids are the best on youtube - keep it going please, best sub ever.

[SobTim-euxu]

First is fire
Second is fire(unless filling, I know this)
Third is like in C#, but without f string
Fourth I know, and also like in C#(unless, .3f, this is fire)
Fifth is fire, this is why I live python)
1year+ of python)
I use it in cryptography, and numerical methods)

[daveys]

I like that print(f’{a + b = }’) one at the end. I can think of a few times when I’d use that.

[nuynobi]

Only the last one is specific to f-strings though, right? The rest are all just general string formatting techniques. Good tips nonetheless.