r语言 - 在API调用中循环列值的问题

Question

我正在研究一个项目，我试图采取一个数据框架，只有一列，其中包含单词，然后试图建立一个循环，将从韦氏API拉一些数据的单词，然后将其放入一个新的数据框架。

最终的数据帧应该是这样的:

name | class | pronunciation | definition
ambit  noun    am*bit          circuit, compass

我的代码:

words_for_loopdataframe

diurnal  
omnibus 
chatelaine 
mantic 
limitrophe 
oaf

代码:

for (i in seq_along(words_for_loop)) {
url_word_vector <- paste("https://www.dictionaryapi.com/api/v3/references/collegiate/json/", words_for_loop[[i]], "?key=numbers", sep = "")

data_holder <- tibble()
data_loop <- fromJSON(url_word_vector, flatten = TRUE) %>% 
select(meta.id, fl, hwi.hw, shortdef) %>% 
dplyr::rename(name = meta.id, class = fl, pronunciation = hwi.hw, definition = shortdef)  

data_holder <-
data_holder %>%
bind_rows(data_loop)
}

结果是一个空标题。我想我是在正确的轨道上，因为运行url_word_vector的结果是:

[1] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/diurnal?key=99820690-b2a0-4aa3-902a-f54c7fa3c685"   
[2] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/omnibus?key=99820690-b2a0-4aa3-902a-f54c7fa3c685"   
[3] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/chatelaine?key=99820690-b2a0-4aa3-902a-f54c7fa3c685"
[4] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/mantic?key=99820690-b2a0-4aa3-902a-f54c7fa3c685"    
[5] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/limitrophe?key=99820690-b2a0-4aa3-902a-f54c7fa3c685"
[6] "https://www.dictionaryapi.com/api/v3/references/collegiate/json/oaf?key=99820690-b2a0-4aa3-902a-f54c7fa3c685" 

我只是不知道如何让它在那些单独的调用上循环。我需要在循环内嵌套一个循环吗?只是在寻找下一步。谢谢!

Answer 1

我认为最好将所有结果列在一个列表中，并在最后对它们进行rbind。

library(dplyr)
library(jsonlite)
words_for_loop <- data.frame(V1 = c("diurnal", "omnibus", "chatelaine", 
"mantic", "limitrophe", "oaf"))
home <- "https://www.dictionaryapi.com/api/v3/references/collegiate/json/"
key <- "my-api-key"
url_word_vector <- paste0(home, words_for_loop[[1]], "?key=", key)
do.call(rbind, lapply(url_word_vector, function(url) {
fromJSON(url, flatten = TRUE) %>% 
select(meta.id, fl, hwi.hw, shortdef) %>% 
rename(name = meta.id, class = fl, pronunciation = hwi.hw, definition = shortdef) %>%
as_tibble()
}))
#> # A tibble: 11 x 4
#>    name              class                     pronunciation          definition
#>    <chr>             <chr>                     <chr>                  <list>    
#>  1 diurnal:1         adjective                 di*ur*nal              <chr [3]> 
#>  2 diurnal:2         noun                      diurnal                <chr [2]> 
#>  3 omnibus:1         noun                      om*ni*bus              <chr [2]> 
#>  4 omnibus:2         adjective                 omnibus                <chr [2]> 
#>  5 justitia omnibus~ Latin phrase              jus*ti*tia om*ni*bus   <chr [1]> 
#>  6 quod semper, quo~ Latin quotation from {i_~ quod sem*per, quod ub~ <chr [1]> 
#>  7 the man on the C~ noun phrase               the man on the Clapha~ <chr [1]> 
#>  8 chatelaine        noun                      chat*e*laine           <chr [3]> 
#>  9 mantic            adjective                 man*tic                <chr [1]> 
#> 10 limitrophe        adjective                 lim*i*trophe           <chr [1]> 
#> 11 oaf               noun                      oaf                    <chr [2]>

^{由reprex包(v2.0.0)在2018-10-29上创建}