CODEWITHSUNDEEP
rregex
milka1117
milka1117

Reputation: 521

Extracting numbers from string in R using regex

I have a string like this:

myString <- "[0.15][4577896]blahblahblahblahwhatever"

I need to extract the number between second brackets.

Currently I am trying to use this:

str_extract(myString, "\\]\\[(\\d+)")

But this gives me ][4577896

My desired result would be: 4577896

How could I achieve this?

Upvotes: 0

Views: 74

Answers (5)

akrun
akrun

Reputation: 886938

An option using str_extract

library(stringr)
str_extract(myString, "(?<=.\\[)([0-9]+)")
#[1] "4577896"

Upvotes: 1

Ronak Shah
Ronak Shah

Reputation: 388807

Here is another version with minimal or no regex

qdapRegex::ex_between_multiple(myString, "[", "]")[[2]]
#[1] "4577896"

It extracts all the substring between [ and ] and we select the value between second bracket. You can convert it into numeric or integer if needed.

Upvotes: 2

boski
boski

Reputation: 2467

With no need of look behinds

gsub(".*\\[(\\d+).*","\\1",myString)
[1] "4577896"

Upvotes: 3

Oliver Hao
Oliver Hao

Reputation: 735

You can try this .(?<=\]\[)(\d+)

This is a demo.https://regex101.com/r/fvHW05/1

Upvotes: 2

Jan
Jan

Reputation: 43169

You may use

^(?:[^\[\]]*\[[^\[\]]+\])[^\]\[]*\[([^\]\[]+).+

And replace this with the first captured group using gsub, see a demo on regex101.com. In base R:

myString <- "[0.15][4577896]blahblahblahblahwhatever"

pattern <- "^(?:[^\\[\\]]*\\[[^\\[\\]]+\\])[^\\]\\[]*\\[([^\\]\\[]+).+"
gsub(pattern, "\\1", myString, perl = T)
# [1] "4577896"

Upvotes: 1

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