如何从 R 访问维基百科？

Question

R 是否有任何包允许查询维基百科（最有可能使用 Mediawiki API）来获取与此类查询相关的可用文章列表，以及导入选定的文章以进行文本挖掘？

Answer 1

有 WikipediR，'R 中的 MediaWiki API 包装器'

library(devtools)
install_github("Ironholds/WikipediR")
library(WikipediR)

它包括这些功能：

ls("package:WikipediR")
 [1] "wiki_catpages"      "wiki_con"           "wiki_diff"          "wiki_page"         
 [5] "wiki_pagecats"      "wiki_recentchanges" "wiki_revision"      "wiki_timestamp"    
 [9] "wiki_usercontribs"  "wiki_userinfo"  

这里正在使用，获取一堆用户的贡献详细信息和用户详细信息：

library(RCurl)
library(XML)

# scrape page to get usernames of users with highest numbers of edits
top_editors_page <- "http://en.wikipedia.org/wiki/Wikipedia:List_of_Wikipedians_by_number_of_edits"
top_editors_table <- readHTMLTable(top_editors_page)
very_top_editors <- as.character(top_editors_table[[3]][1:5,]$User)

# setup connection to wikimedia project 
con <- wiki_con("en", project = c("wikipedia"))

# connect to API and get last 50 edits per user
user_data <- lapply(very_top_editors,  function(i) wiki_usercontribs(con, i) )
# and get information about the users (registration date, gender, editcount, etc)
user_info <- lapply(very_top_editors,  function(i) wiki_userinfo(con, i) )

Answer 2

使用 RCurl 包来检索信息，使用 XML 或 RJSONIO 包来解析响应。

如果您使用代理，请设置您的选项。

opts <- list(
  proxy = "136.233.91.120", 
  proxyusername = "mydomain\\myusername", 
  proxypassword = 'whatever', 
  proxyport = 8080
)

使用 getForm 函数访问API 。

search_example <- getForm(
  "http://en.wikipedia.org/w/api.php", 
  action  = "opensearch", 
  search  = "Te", 
  format  = "json",
  .opts   = opts
)

解析结果。

fromJSON(rawToChar(search_example))

Answer 3

一个新的伟大可能性是 wikifacts 包（在 CRAN 上）：

library(wikifacts)
wiki_define('R (programming language)')
## R (programming language) 
## "R is a programming language and free software environment for statistical computing and graphics supported by the R Foundation for Statistical Computing. The R language is widely used among statisticians and data miners for developing statistical software and data analysis. Polls, data mining surveys, and studies of scholarly literature databases show substantial increases in popularity; as of April 2021, R ranks 16th in the TIOBE index, a measure of popularity of programming languages.The official R software environment is a GNU package.\nIt is written primarily in C, Fortran, and R itself (thus, it is partially self-hosting) and is freely available under the GNU General Public License. Pre-compiled executables are provided for various operating systems."