如何解析非xml为xml？

Question

http://api.bart.gov/api/stn.aspx?cmd=stns&key=MW9S-E7SL-26DU-VV8V

如何将此端口作为XML文档移植？我试图在R中解析这个。

Answer 1

使用库rvest。该基地的想法是找到与XPath选择感兴趣的节点（xml_nodes），然后抓住值与xml_text

library(rvest) 

doc <- read_xml("http://api.bart.gov/api/stn.aspx?cmd=stns&key=MW9S-E7SL-26DU-VV8V") 
names <- doc %>% 
    xml_nodes(xpath = "/root/stations/station/name") %>% 
    xml_text() 

names[1:5] 

# [1] "12th St. Oakland City Center" "16th St. Mission"    "19th St. Oakland"    "24th St. Mission"    
# [5] "Ashby"      

Answer 2

我不得不使用内read_html直接的URL一些问题。所以我先用readLines。之后，它找到与<station>的所有节点集。将其转换为列表并将其送入data.table::rbindlist。使用rbindlist的想法来自here来到

library(xml2) 
library(data.table) 
nodesets <- read_html(readLines("http://api.bart.gov/api/stn.aspx?cmd=stns&key=MW9S-E7SL-26DU-VV8V")) %>% 
    xml_find_all(".//station") 
data.table::rbindlist(as_list(nodesets)) 

Answer 3

您可以使用XML2读取和解析：

library(xml2) 
library(tidyverse) 

xml <- read_xml('https://api.bart.gov/api/stn.aspx?cmd=stns&key=MW9S-E7SL-26DU-VV8V') 

bart <- xml %>% xml_find_all('//station') %>% # select all station nodes 
    map_df(as_list) %>% # coerce each node to list, collect to data.frame 
    unnest() # unnest list columns of data.frame 

bart 
#> # A tibble: 46 × 9 
#>       name abbr gtfs_latitude gtfs_longitude 
#>       <chr> <chr>   <chr>   <chr> 
#> 1 12th St. Oakland City Center 12TH  37.803768 -122.271450 
#> 2    16th St. Mission 16TH  37.765062 -122.419694 
#> 3    19th St. Oakland 19TH  37.808350 -122.268602 
#> 4    24th St. Mission 24TH  37.752470 -122.418143 
#> 5       Ashby ASHB  37.852803 -122.270062 
#> 6     Balboa Park BALB  37.721585 -122.447506 
#> 7      Bay Fair BAYF  37.696924 -122.126514 
#> 8     Castro Valley CAST  37.690746 -122.075602 
#> 9   Civic Center/UN Plaza CIVC  37.779732 -122.414123 
#> 10      Coliseum COLS  37.753661 -122.196869 
#> # ... with 36 more rows, and 5 more variables: address <chr>, city <chr>, 
#> # county <chr>, state <chr>, zipcode <chr>