在 function 中检索 google 学者 ID

Question

I've got a list of scholars for parse their available Google scholar ID's. Somehow I obtain the error of "subscript out of bounds", but I can't relate to other responses provided with this issue. Code as follows. Thanks::

library(scholar)
    for (i in 1:200){
  
  scholars<-get_scholar_id(last_name = list$Last.Name[i], 
                 first_name = list$First.Name[i],
                 affiliation = "ABC University")
}

This results in:

No Scholar ID found.
No Scholar ID found.
Error in tables[[1]] : subscript out of bound

However, if I do put:

  scholars_B<-get_scholar_id(last_name = list$Last.Name[3], 
                 first_name = list$First.Name[3],
                 affiliation = "ABC University")

I obtain the Google scholar ID without any issues.

Reproducible example:

# list from top h-index researchers (just for the purpose of this sample)

Last.Name <- c("Colditz", "Lander", "Akira", "Langer", "Karin")
First.Name <- c("Graham", "Eric", "Shizuo", "Robert", "Michael")
df <- data.frame(Last.Name, First.Name)
print (df)


library(scholar)

#First try: 
for(i in 1:3){
  
  scholars<-get_scholar_id(last_name = df$Last.Name[i], 
                           first_name = df$First.Name[i])
}

#Error: Error in tables[[1]] : subscript out of bounds


#Suggestion by @akrun

for(i in seq_along(df$Last.Name)){
  
  scholars<-get_scholar_id(last_name = df$Last.Name[i], 
                           first_name = df$First.Name[i])
}

#Error: Error in tables[[1]] : subscript out of bounds

#This way works, but not with the for function: 

scholars<-get_scholar_id(last_name = df$Last.Name[3], 
                           first_name = df$First.Name[3])
print(scholars)

Answer 1

Some elements doesn't have the scholar id and it is returning with an error. An option is to bypass those cases with a tryCatch or possibly (from purrr )

library(purrr)
library(scholar)
p_get_scholar_id <- possibly(get_scholar_id, otherwise = NA_character_)
scholars <- character(nrow(df))
for(i in seq_along(scholars)) {
  scholars[i] <- p_get_scholar_id(last_name = df$Last.Name[i], 
                       first_name = df$First.Name[i])
  }

-output

scholars
#[1] NA             "LXVfPc8AAAAJ" "0TG2laoAAAAJ" NA             "xVvyb1gAAAAJ"