Comment #0 by bearophile_hugs — 2013-06-08T15:19:30Z
If I have a string as "10,20,30" and I need to split it taking the part after the last comma and all before it, in Python I use rsplit() with optional argument 1:
>>> s = "10,20,30"
>>> a, b = s.rsplit(",", 1)
>>> assert a, b == "10,20", "30"
The optional second argument tells Python when to stop splitting, and the "r" suffix of split means "from the right":
>>> "10,20,30,40,50".rsplit(",", 2)
['10,20,30', '40', '50']
>>> "10,20,30,40,50".split(",", 2)
['10', '20', '30,40,50']
One (awkward) way to do the same thing in D+Phobos is:
import std.algorithm: find;
import std.range: retro;
void main() {
auto s = "10,20,30";
string a = s.retro.find(",").retro[0 .. $ - 1];
string b = s[a.length + 1 .. $];
assert (a == "10,20");
assert(b == "30");
}
I don't see a rsplit or rSplit or rightSplit in std.string, but I see findSplitAfter and findSplitBefore in std.algorithm:
s.findSplitAfter(",")
==>
Tuple!(string, string)("10,", "20,30")
s.findSplitBefore(",")
==>
Tuple!(string, string)("10", ",20,30")
If I use std.range.retro:
s.retro.findSplitBefore(",")
==>
Tuple!(Result, Result)(03, ,02,01)
Also notice the lack of " inside the tuple, those aren't strings.
And indeed this is not accepted:
s.retro.findSplitBefore(",")[0].retro
If I am not missing something from Phobos, then maybe it's a good idea to add a rSplit(string,count=-1) (or rightSplit) to std.string or std.array (and maybe add a second argument to std.array.split as in Python).
Comment #1 by robert.schadek — 2024-12-01T16:17:54Z