在 R 中按字符串格式过滤

Question

I have an ID column that should always be formatted ABCDE123 - Five letters and three numbers, no gap no symbols.

I know for sure there are a number of rows that don't correctly follow this format. Is it possible to filter by the string format in R, so that I can identify those rows and review them?

Tidyverse is preferred, but any solution would be helpful!

Answer 1

If these are 5 upper case letters followed by 3 digits, specify regex to match 5 upper case letters [AZ]{5} from the start ( ^ ) of the string followed by 3 digits ( [0-9]{3} ) at the end ( $ ) of the string in str_detect to return a logical vector which is used in filter ing the rows of the data

library(dplyr)
library(stringr)
df1 %>%
    filter(str_detect(ID, '^[A-Z]{5}[0-9]{3}$'))

---

If these rows should be removed, specify negate = TRUE in str_detect

df1 %>%
    filter(str_detect(ID, '^[A-Z]{5}[0-9]{3}$', negate = TRUE))

Or as @BenBolker mentioned in the comments [[:upper:]]{5} would be more generic compared to [AZ]{5}