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从R中的url下载多个.csv

data-manipulation r

Seyma Kalay · 技术社区 · 5 年前

我有多个 .csv 数据集,我想上传它们并用不同的名称保存它们。提前感谢。

casualty_2005 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2005-gla-data-extract-casualty.csv", header=T)
casualty_2006 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2006-gla-data-extract-casualty.csv", header=T)
casualty_2007 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2007-gla-data-extract-casualty.csv", header=T)
casualty_2008 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2008-gla-data-extract-casualty.csv", header=T)
casualty_2009 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2009-gla-data-extract-casualty.csv", header=T)
casualty_2010 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2010-gla-data-extract-casualty.csv", header=T)
casualty_2011 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2011-gla-data-extract-casualty.csv", header=T)
casualty_2012 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2012-gla-data-extract-casualty.csv", header=T)
casualty_2013 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2013-gla-data-extract-casualty.csv", header=T)
casualty_2014 <- read.csv("https://tfl.gov.uk/cdn/static/cms/documents/2014-gla-data-extract-casualty.csv", header=T)

0 回复 | 直到 5 年前

Rui Barradas 5 年前

类似的问题已经被问过很多次了,创建一个名称/链接向量,然后读取 lapply 循环。
请注意 read.csv 的默认值为 header = TRUE .

url_fmt <- "https://tfl.gov.uk/cdn/static/cms/documents/%04d-gla-data-extract-casualty.csv"
url_years <- 2005:2014
url_vec <- sprintf(url_fmt, url_years)
df_list <- lapply(url_vec, read.csv)
names(df_list) <- url_years

head(df_list[[1]])       # first file, top 6 rows
head(df_list[["2005"]])  # same file
head(df_list$`2005`)     # same file

编辑

阅读后 doctshind s answer ,我意识到问题在于如何下载文件,而不是如何阅读他们。

设置新目录的说明是可选的。

#old_dir <- getwd()
#setwd('~/tmp')

lapply(url_vec, function(x) download.file(x, destfile = basename(x)))
list.files(pattern = '\\.csv')
# [1] "2005-gla-data-extract-casualty.csv"
# [2] "2006-gla-data-extract-casualty.csv"
# [3] "2007-gla-data-extract-casualty.csv"
# [4] "2008-gla-data-extract-casualty.csv"
# [5] "2009-gla-data-extract-casualty.csv"
# [6] "2010-gla-data-extract-casualty.csv"
# [7] "2011-gla-data-extract-casualty.csv"
# [8] "2012-gla-data-extract-casualty.csv"
# [9] "2013-gla-data-extract-casualty.csv"
#[10] "2014-gla-data-extract-casualty.csv"

#setwd(old_dir)

doctshind s 5 年前

以下是完整可用的代码及其解释:

# List of File URLs
urlist <- list("https://tfl.gov.uk/cdn/static/cms/documents/2005-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2006-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2007-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2008-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2009-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2010-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2011-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2012-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2013-gla-data-extract-casualty.csv","https://tfl.gov.uk/cdn/static/cms/documents/2014-gla-data-extract-casualty.csv")
setwd("~/so")
#for loop to select each url and store them
for (i in 1: length(urlist)) {
#define path to download
#get filename from the url path
destfile<-basename(urlist[[i]])
#download current file
download.file(urlist[[i]]), destfile)
}