XPath, select 两个连续的元素并将它们转化为一个数据框
XPath, select two consecutive elements and transform them into one data frame
总的来说，我对 Path 和 R 真的很陌生，我正在尝试使用 XPath 将 XML 文件转换为 R 中的数据框。在一些帮助下，我设法转换了 XML 中的大部分信息=29=] 已经。但是，现在我正在尝试获取两个连续的元素并将它们合并到一个数据框中。不知何故，我似乎做对了。
这是 xml 数据的摘录：
</customer-bootstrap-data>
<customer-bootstrap-data id="970911" customerName="HighIncome-1_4" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.1124173640233721,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.37606842556525066,-0.0,-0.0,-0.038684343289247636,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.8490012729862713,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
<customer-bootstrap-data id="970912" customerName="HighIncome-2_17" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.21395291779884928,-0.0,-0.0,-1.3581716633726693,-0.0,-0.0,-2.8140822306420716,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.0221045637055397,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-3.3,-3.223543705462774,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.153329511039221,-0.0,-0.0,-0.0,-0.0,-0.0,-0.820425411761537,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.7054631085029754,-0.0,-0.7130641168720118,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-2.5003661751788435,-0.0,-0.0,-3.3,-3.3,-0.6606989045692728,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.20818145620010853,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0493154269844851,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.0,-1.041919182358086,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.5334016276259916,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
我可以使用以下代码生成第一个元素的 table：
customerBoot <- xpathSApply(doc=xml, path=("//customer-bootstrap-data"), xmlAttrs)
customerBoot <- data.frame(t(customerBoot))
包含 id、customerName 和 powerType。但我希望每个客户 ID 也包含净使用量。
以下代码选择了我想要的所有信息，只是不允许我将其转换为数据框。
customerBoot <- getNodeSet(xml,"//customer-bootstrap-data")
有任何想法吗？我正在寻找一个快速的解决方案。
谢谢！
让我知道这是否有速度问题（以这种方式遍历巨大的 XML 文档有时会很慢）：
library(XML)
library(purrr)
fil <- '<dat><customer-bootstrap-data id="970911" customerName="HighIncome-1_4" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.1124173640233721,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.37606842556525066,-0.0,-0.0,-0.038684343289247636,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.8490012729862713,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
<customer-bootstrap-data id="970912" customerName="HighIncome-2_17" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.21395291779884928,-0.0,-0.0,-1.3581716633726693,-0.0,-0.0,-2.8140822306420716,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.0221045637055397,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-3.3,-3.223543705462774,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.153329511039221,-0.0,-0.0,-0.0,-0.0,-0.0,-0.820425411761537,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.7054631085029754,-0.0,-0.7130641168720118,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-2.5003661751788435,-0.0,-0.0,-3.3,-3.3,-0.6606989045692728,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.20818145620010853,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0493154269844851,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.0,-1.041919182358086,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.5334016276259916,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data></dat>'
doc <- xmlParse(fil)
customerBoot <- xpathSApply(doc=doc, path="//customer-bootstrap-data", xmlAttrs)
customerBoot <- data.frame(t(customerBoot), stringsAsFactors=FALSE)
# go by row using the id, grab the desired data node, convert it to a wide data.frame
customerBoot <- purrr::by_row(customerBoot, function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x$id)
vals <- strsplit(xpathSApply(doc=doc, path=path, xmlValue), ",")[[1]]
as.numeric(vals)
}, .to="X", .collate="cols")
# limiting the "str()" equivalent "glimpse()" to 15 columns since there are >300 of them:
dplyr::glimpse(customerBoot[, 1:15])
## Observations: 2
## Variables: 15
## $ id (chr) "970911", "970912"
## $ customerName (chr) "HighIncome-1_4", "HighIncome-2_17"
## $ powerType (chr) "ELECTRIC_VEHICLE", "ELECTRIC_VEHICLE"
## $ X1 (dbl) 0, 0
## $ X2 (dbl) 0, 0
## $ X3 (dbl) 0, 0
## $ X4 (dbl) 0, 0
## $ X5 (dbl) 0, 0
## $ X6 (dbl) 0, 0
## $ X7 (dbl) 0, 0
## $ X8 (dbl) 0.0000000, -0.2139529
## $ X9 (dbl) 0, 0
## $ X10 (dbl) 0, 0
## $ X11 (dbl) 0.000000, -1.358172
## $ X12 (dbl) 0, 0
xml2的替代方法：
library(purrr)
library(xml2)
doc <- read_xml(fil)
xml_find_all(doc, "//customer-bootstrap-data") %>%
xml_attrs() %>%
map_df(function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x["id"])
vals <- strsplit(xml_text(xml_find_one(doc, path)), ",")[[1]]
vals <- setNames(as.numeric(vals), sprintf("X%d", 1:length(vals)))
rbind.data.frame((c(as.list(x), as.list(vals))), stringsAsFactors=FALSE)
})
更新：
当 netUsage 长度不一致时，这是一种方法：
data.table::rbindlist(apply(customerBoot, 1, function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x["id"])
vals <- strsplit(xpathSApply(doc=doc, path=path, xmlValue), ",")[[1]]
c(as.list(x), as.list(setNames(as.numeric(vals), sprintf("X%d", 1:length(vals)))))
}), fill=TRUE)
总的来说，我对 Path 和 R 真的很陌生，我正在尝试使用 XPath 将 XML 文件转换为 R 中的数据框。在一些帮助下，我设法转换了 XML 中的大部分信息=29=] 已经。但是，现在我正在尝试获取两个连续的元素并将它们合并到一个数据框中。不知何故，我似乎做对了。
这是 xml 数据的摘录：
</customer-bootstrap-data>
<customer-bootstrap-data id="970911" customerName="HighIncome-1_4" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.1124173640233721,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.37606842556525066,-0.0,-0.0,-0.038684343289247636,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.8490012729862713,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
<customer-bootstrap-data id="970912" customerName="HighIncome-2_17" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.21395291779884928,-0.0,-0.0,-1.3581716633726693,-0.0,-0.0,-2.8140822306420716,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.0221045637055397,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-3.3,-3.223543705462774,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.153329511039221,-0.0,-0.0,-0.0,-0.0,-0.0,-0.820425411761537,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.7054631085029754,-0.0,-0.7130641168720118,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-2.5003661751788435,-0.0,-0.0,-3.3,-3.3,-0.6606989045692728,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.20818145620010853,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0493154269844851,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.0,-1.041919182358086,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.5334016276259916,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
我可以使用以下代码生成第一个元素的 table：
customerBoot <- xpathSApply(doc=xml, path=("//customer-bootstrap-data"), xmlAttrs)
customerBoot <- data.frame(t(customerBoot))
包含 id、customerName 和 powerType。但我希望每个客户 ID 也包含净使用量。
以下代码选择了我想要的所有信息，只是不允许我将其转换为数据框。
customerBoot <- getNodeSet(xml,"//customer-bootstrap-data")
有任何想法吗？我正在寻找一个快速的解决方案。
谢谢！
让我知道这是否有速度问题（以这种方式遍历巨大的 XML 文档有时会很慢）：
library(XML)
library(purrr)
fil <- '<dat><customer-bootstrap-data id="970911" customerName="HighIncome-1_4" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.1124173640233721,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.37606842556525066,-0.0,-0.0,-0.038684343289247636,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.8490012729862713,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data>
<customer-bootstrap-data id="970912" customerName="HighIncome-2_17" powerType="ELECTRIC_VEHICLE">
<netUsage>0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.21395291779884928,-0.0,-0.0,-1.3581716633726693,-0.0,-0.0,-2.8140822306420716,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.0221045637055397,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-3.3,-3.223543705462774,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.153329511039221,-0.0,-0.0,-0.0,-0.0,-0.0,-0.820425411761537,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.7054631085029754,-0.0,-0.7130641168720118,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-2.5003661751788435,-0.0,-0.0,-3.3,-3.3,-0.6606989045692728,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.20818145620010853,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0493154269844851,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.0,-1.041919182358086,-0.0,-0.0,-0.0,-0.0,-0.0,-0.0,-3.3,-0.5334016276259916,-0.0,-0.0,-0.0</netUsage>
</customer-bootstrap-data></dat>'
doc <- xmlParse(fil)
customerBoot <- xpathSApply(doc=doc, path="//customer-bootstrap-data", xmlAttrs)
customerBoot <- data.frame(t(customerBoot), stringsAsFactors=FALSE)
# go by row using the id, grab the desired data node, convert it to a wide data.frame
customerBoot <- purrr::by_row(customerBoot, function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x$id)
vals <- strsplit(xpathSApply(doc=doc, path=path, xmlValue), ",")[[1]]
as.numeric(vals)
}, .to="X", .collate="cols")
# limiting the "str()" equivalent "glimpse()" to 15 columns since there are >300 of them:
dplyr::glimpse(customerBoot[, 1:15])
## Observations: 2
## Variables: 15
## $ id (chr) "970911", "970912"
## $ customerName (chr) "HighIncome-1_4", "HighIncome-2_17"
## $ powerType (chr) "ELECTRIC_VEHICLE", "ELECTRIC_VEHICLE"
## $ X1 (dbl) 0, 0
## $ X2 (dbl) 0, 0
## $ X3 (dbl) 0, 0
## $ X4 (dbl) 0, 0
## $ X5 (dbl) 0, 0
## $ X6 (dbl) 0, 0
## $ X7 (dbl) 0, 0
## $ X8 (dbl) 0.0000000, -0.2139529
## $ X9 (dbl) 0, 0
## $ X10 (dbl) 0, 0
## $ X11 (dbl) 0.000000, -1.358172
## $ X12 (dbl) 0, 0
xml2的替代方法：
library(purrr)
library(xml2)
doc <- read_xml(fil)
xml_find_all(doc, "//customer-bootstrap-data") %>%
xml_attrs() %>%
map_df(function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x["id"])
vals <- strsplit(xml_text(xml_find_one(doc, path)), ",")[[1]]
vals <- setNames(as.numeric(vals), sprintf("X%d", 1:length(vals)))
rbind.data.frame((c(as.list(x), as.list(vals))), stringsAsFactors=FALSE)
})
更新：
当 netUsage 长度不一致时，这是一种方法：
data.table::rbindlist(apply(customerBoot, 1, function(x) {
path <- sprintf("//customer-bootstrap-data[@id='%s']/netUsage", x["id"])
vals <- strsplit(xpathSApply(doc=doc, path=path, xmlValue), ",")[[1]]
c(as.list(x), as.list(setNames(as.numeric(vals), sprintf("X%d", 1:length(vals)))))
}), fill=TRUE)