从变量R

Question

我正在寻找一些帮助，可以在数据框中创建来自多个名称变量的电子邮件。想知道是否有快速方法用正则表达式做到这一点？请注意，需要包含id。例如，if id == 1, return an email address is the following format: tim.c.smith@email.com.非常感谢任何人提供的任何帮助。

#Starting
id = c(1,2)
firstnm = c("tim", "mary") 
midnm = c("chris","sally") 
lastnm = c("smith","jane") 
email = c("","") 
st_df = data.frame(id,firstnm,midnm,lastnm,email)


#Ending
id = c(1,2)
firstnm = c("tim", "mary") 
midnm = c("chris","sally") 
lastnm = c("smith","jane") 
email = c("tim.c.smith@email.com","mary.jane@email.com") 
end_df = data.frame(id,firstnm,midnm,lastnm,email)

Answer 1

我们可以ifelse

st_df$email <- with(st_df, ifelse(id==1, paste0(firstnm, ".", 
      substr(midnm, 1, 1),".", lastnm, "@email.com"),
       paste0(firstnm, ".", lastnm, "@email.com")) )
st_df$email
#[1] "tim.c.smith@email.com" "mary.jane@email.com"