Separate column with conditions Using R

Question

i have dataset for meals have visitor, meal, meal_code, some meal rows have both meal and meal_code and the meal_code filled from the above row.

The 2nd row contain the issue.

visitor	meal	meal_code
ahmed	water	w1
ahmed	s1 sandwich	w1
khaled	fish	f1
khaled	2extra coffee	c2

I want move the meal_code from meal if have code and fill right. Note that some meal name have number and all meal_code must have number.

I have tried sep = "\\\\s(?=.\*\\\\d) but not work.

Answer 1

As you said the meal codes could be c2 or c2.1, you can try the following stringr solution:

library(dplyr)
library(stringr)

df %>%
  mutate(meal_code = coalesce(str_extract(meal, "[a-z]+[0-9.]+"), meal_code),
         meal = str_squish(str_remove(meal, meal_code)))

# # A tibble: 4 × 3
#   visitor meal          meal_code
#   <chr>   <chr>         <chr>    
# 1 ahmed   water         w1       
# 2 ahmed   sandwich      s1       
# 3 khaled  fish          f1       
# 4 khaled  2extra coffee c2