stringr package str_extract() with inversion of the regex

Question

I have a string like the following: 14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27.0

The following regex extracts the last part that ends in a dot and a digit. I want to extract everything but that part and can't seem to find a way to invert the regex (using ^) is not helping:

> s <- '14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27.0'
> str_extract(s, '(\\.[0-9]{1})$')
[1] ".0"

I instead want the output to be:

[1] 14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27

To clarify further, I want it to return the string as is, if it does not end in a dot and one single digit.

Following example:

> s <- '14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27'
> str_extract(s, someRegex)
[1] "14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27"
> s <- '14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27.1'
> str_extract(s, someRegex)
[1] "14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27"
> s <- '14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27.4'
> str_extract(s, someRegex)
[1] "14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27"

score 1 · Accepted Answer · 2015-08-28T18:17:57.320

1

Try this regex:

^.*(?=\.\d+$)|^.*

Regex live here.

edited Aug 28 '15 at 18:17

answered Aug 28 '15 at 17:58

I can edit the question, but I don't want it to chop off anything that ends in more than one digit after the last '.' – Gopala Aug 28 '15 at 18:01
@user3949008. Sorry for that. – Aug 28 '15 at 18:18

score 1 · Answer 2 · answered Aug 28 '15 at 18:39

1

One option would be substituting for the last bit,

sub("\\.\\d$", '', s)

answered Aug 28 '15 at 18:39

Rorschach

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XOR-Manik · Answer 3 · 2015-08-28T18:33:35.690

0

str_extract(s, ([\w ]+(?:\.|\-)){7})

Then you can access the returned string to its lenght-1, and it will give you the required output!

PS: You may have to use escape characters.

edited Aug 28 '15 at 18:33

answered Aug 28 '15 at 17:56

XOR-Manik

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score 0 · Answer 4 · answered Oct 11 '21 at 22:48

0

You could use stringr::str_remove() for example:

s <- '14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27.0'
stringr::str_remove(s, '(\\.[0-9]{1})$')
#> [1] "14ed0d69fa2.bbd.7f5512.filter-132.21026.55B67C8E27"

answered Oct 11 '21 at 22:48

Bryan Shalloway

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stringr package str_extract() with inversion of the regex

4 Answers4