Split String with second (single) Backslash / R Emojis (Unicode) without Modifier

user_16337230 0
Viewed 113

I have a tribble with a chr column that contains the unicode to emojis. I want to split these strings into two columns in case of need, if there are more than two backslash in the whole string. So I need a split with the 2nd backslash. It would also be enough to just delete everything from the 2nd backslash on.

Here is what I tried:

df <- tibble::tribble(
  ~RUser, ~REmoji,
  "User1", "\U0001f64f\U0001f3fb",
  "User2", "\U0001f64f",
  "User2", "\U0001f64f\U0001f3fc"
)

df %>% mutate(newcol = gsub("\\\\*", "", REmoji))

I found the solution Replace single backslash in R. But in my case I have only one backslash, and I don't understand how to separate the column here.

The result should look like this output:

df2 <- tibble::tribble(
  ~RUser, ~REmoji1, ~newcol,
  "User1", "\U0001f64f", "\U0001f3fb",
  "User2", "\U0001f64f", "", #This Field is empty, since there was no Emoji-Modification
  "User2", "\U0001f64f", "\U0001f3fc"
)

Thanks a lot!

r replace split regex string
2 Answers

We could also use substring from base R

df$newcol <- substring(df$REmoji, 2)
user_37322710

Note these \U... are single Unicode code points, not just a backslash + digits/letters.

Using the ^. PCRE regex with sub provides the expected results:

> df %>% mutate(newcol = sub("^.", "", REmoji, perl=TRUE))
# A tibble: 3 x 3
  RUser REmoji                 newcol      
  <chr> <chr>                  <chr>       
1 User1 "\U0001f64f\U0001f3fb" "\U0001f3fb"
2 User2 "\U0001f64f"           ""          
3 User2 "\U0001f64f\U0001f3fc" "\U0001f3fc"

Make sure you pass the perl=TRUE argument.

And in order to do the reverse, i.e. keep the first code point only, you can use:

df %>% mutate(newcol = sub("^(.).+", "\\1", REmoji, perl=TRUE))
user_38329700
Related