我想下载一个压缩在 open-plaques-all-2017-06-19.rar 中的文件，但未能在 R 中实现。请看下面我的代码
temp <- tempfile()
download.file("https://github.com/tuyenhavan/Statistics/blob/master/open-plaques-all-2017-06-19.rar", temp)
df<- fread(unzip(temp, files = "open-plaques-all-2017-06-19.csv"))
head(df)
【问题讨论】：
标签： r import zip data-extraction
对于这些相应的平台/pkg 管理器，您需要：
Windows 用户会为他们自动下载预编译的二进制文件。
然后做：
devtools::install_github("jimhester/archive")
这是一个工作流程。现在您指定的 URL 不正确/无效。您需要使用“原始”URL 来访问实际文件。
library(archive)
tf1 <- tempfile(fileext = ".rar")
download.file("https://github.com/tuyenhavan/Statistics/blob/master/open-plaques-all-2017-06-19.rar?raw=true", tf1)
tf2 <- tempfile()
archive_extract(tf1, tf2)
list.files(tf2)
## [1] "open-plaques-all-2017-06-19.csv"
file.size(file.path(tf2, list.files(tf2)))
## [1] 26942816
xdf <- readr::read_csv(file.path(tf2, list.files(tf2)))
dplyr::glimpse(xdf)
## Observations: 38,436
## Variables: 27
## $ id <int> 29923, 42945, 42944, 42943, 42942, 42941, 42940, ...
## $ title <chr> "Jon Pertwee blue plaque", "Apsley Cherry-Garrard...
## $ inscription <chr> "Jon Pertwee 1919-1996 Doctor Who 1970-1974", "Ap...
## $ latitude <dbl> NA, NA, NA, NA, NA, NA, 54.14910, 45.76330, NA, 4...
## $ longitude <dbl> NA, NA, NA, NA, NA, NA, -4.46938, 4.83157, NA, 4....
## $ country <chr> "United Kingdom", "United Kingdom", "United Kingd...
## $ area <chr> "London", "Bedford", "Harlow", "Bozen", "Adro", "...
## $ address <chr> "BBC Television Centre", "Lansdowne Road", "The W...
## $ erected <int> NA, NA, NA, NA, NA, 2016, NA, NA, NA, NA, NA, NA,...
## $ main_photo <chr> NA, "https://commons.wikimedia.org/wiki/Special:F...
## $ colour <chr> "blue", "blue", "blue", "brass", "brass", "brass"...
## $ organisations <chr> "[]", "[]", "[\"Harlow Civic Society\"]", "[\"Gun...
## $ language <chr> "English", "English", "English", "Italian", "Ital...
## $ series <chr> NA, NA, NA, "Stolpersteine Italiano", "Stolperste...
## $ series_ref <chr> NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, N...
## $ `geolocated?` <chr> "false", "false", "false", "false", "false", "fal...
## $ `photographed?` <chr> "false", "true", "false", "true", "true", "true",...
## $ number_of_subjects <int> 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0...
## $ lead_subject_name <chr> "Jon Pertwee", "Apsley Cherry-Garrard", NA, NA, "...
## $ lead_subject_born_in <int> 1919, 1886, NA, NA, 1911, 1913, NA, 1888, 1832, 1...
## $ lead_subject_died_in <int> 1996, 1959, NA, NA, 1945, 1945, NA, 1967, 1898, 1...
## $ lead_subject_type <chr> "man", "man", NA, NA, "man", "man", NA, "man", "m...
## $ lead_subject_roles <chr> "[\"Doctor Who\", \"actor\", \"entertainer\", \"t...
## $ lead_subject_wikipedia <chr> "https://en.wikipedia.org/wiki/Jon_Pertwee", "htt...
## $ lead_subject_dbpedia <chr> "http://dbpedia.org/resource/Jon_Pertwee", "http:...
## $ lead_subject_image <chr> "https://commons.wikimedia.org/wiki/Special:FileP...
## $ subjects <chr> "[\"Jon Pertwee|(1919-1996)|man|Doctor Who, actor...
考虑 unlink()ing tf1，将文件从 tf2 复制到更永久的地方，然后在工作完成后清理 unlink()ing tf2。
【讨论】：
我不知道是否有用于提取 RAR 存档的 R 库，但如果您安装了 unrar、unar、p7zip 或类似的东西，您可以通过系统调用调用它们并拥有它们提取文件。
此外，您需要在 url 的末尾标记 ?raw=true 以获取原始数据（而不是 html 代码）。
这是在 mac 上使用 p7zip 或 unar，其他实用程序和系统可能需要不同的语法。
temp <- tempfile()
download.file(paste0("https://github.com/tuyenhavan/Statistics/blob/master/",
"open-plaques-all-2017-06-19.rar?raw=true"), temp)
#list all csv-files in current working directory
csv_files <- list.files(pattern="\\.csv")
#extract RAR to current working directory using p7zip
system(paste("7z x", temp, paste0("-o", getwd())))
#extract RAR to current working directory using unar
system(paste("unar", "-f", "-o", shQuote(getwd()), shQuote(temp)))
#find the name of the extracted csv file
csv_new <- setdiff(list.files(pattern="\\.csv"), csv_files)
#read in the csv as a data.frame
csv.dtf <- read.csv(csv_new)
你也可以直接在csv中读取，但是比较慢。
csv <- system(paste("7z x -so", temp), intern=TRUE)
csv.dtf <- read.csv(text=csv)
【讨论】：