Search numeric value upto 3 words before a particular word-CodePudding

Is it possible to search for numeric value upto 3 words before a particular word let's say years via regex? In the example below I am searching for a word before years, it works but if you look at third element it returns more. Here I need 2 instead. Pattern of XX or more years is not fixed, hence I am trying to find numeric value upto 3 words before years

Description <- c("Candidate having bachelor degree. Minimum 5 years in R", "Excellent academic background plus 3 years of experience in Python", "Analytics Professionals having minimum of 2 or more years of experience", "Candidate possessing credit risk experience plus 2  years in Python", "Candidate possessing credit risk experience plus two or more years in Python")

[1] "Candidate having bachelor degree. Minimum 5 years in R"                      
[2] "Excellent academic background plus 3 years of experience in Python"          
[3] "Analytics Professionals having minimum of 2 or more years of experience"     
[4] "Candidate possessing credit risk experience plus 2  years in Python"         
[5] "Candidate possessing credit risk experience plus two or more years in Python"

Code

str_extract(Description, "\\w (\\ )?(?=  years(\\s of)?(\\s programming|experience)?\\b)")
[1] "5"    "3"    "more" "2 "

CodePudding user response：

We may use a named vector to replace the english elements to numeric, and then do the extraction

library(stringr)
library(english)
as.numeric(str_replace(str_replace_all(Description, 
    setNames(as.character(1:9), as.character(english(1:9)))), 
    ".*\\b([0-9] )\\b[^0-9] \\byears.*", "\\1"))

-output

[1] 5 3 2 2 2