python performance string-formatting f-string edited Aug 17, 2022 at 7:09 Karl Knechtel 61.5k 14 134 194

f-strings are new in python 3.6 and are literals not callables. I know how to get something that works similarly. What I want is to make an existing string (possibly loaded from a file) and have it be a …

Unlike f -strings, the {...} placeholders are not expressions and you can't use arbitrary Python expressions in the template. This is a good thing, you wouldn't want end-users to be able to execute …

Oct 4, 2019 · 5 String starting with f are formatted string literals. Suppose you have a variable: pi = 3.14 To concatenate it to a string you'd do: s = "pi = " + str(pi) Formatted strings come in handy here. …

Jun 27, 2017 · The other answers give ideas for how to put the newline character into a f-string field. However, I would argue that for the example the OP gave (which may or may not be indicative of …

I don't think formatted string literals allowing nesting (by nesting, I take it to mean f'{f".."}') is a result of careful consideration of possible use cases; I'm more convinced it's just allowed in order for them to …

Jun 26, 2017 · An f-string is syntax, not an object type. You can't convert an arbitrary string to that syntax, the syntax creates a string object, not the other way around. I'm assuming you want to use …

Mar 2, 2016 · This little f before the " (double-quote) and the {} characters tell python 3, "hey, this string needs to be formatted. So put these variable in there and format it.".

An f-string isn't a kind of string, it's a kind of string literal, which is evaluated immediately. You can't store an f-string in a variable to be evaluated later, or accept one from a user, etc. 1 This is the only reason …

f-strings (python 3) You can avoid having to double the curly brackets by using f-strings ONLY for the parts of the string where you want the f-magic to apply, and use regular (dumb) strings for everything …