带有嵌套兄弟节点的xml到R中的数据框

Question

我是在R中解析XML的新手.我正在尝试将XML解析为可行的数据框.我已经尝试了XML包中的一些XPath函数,但似乎无法得出正确的答案.

这是我的XML:

<ResidentialProperty>
    <Listing>
      <StreetAddress>
        <StreetNumber>11111</StreetNumber>
        <StreetName>111th</StreetName>
        <StreetSuffix>Avenue Ct</StreetSuffix>
        <StateOrProvince>WA</StateOrProvince>
      </StreetAddress>
      <MLSInformation>
        <ListingStatus Status="Active"/>
        <StatusChangeDate>2015-07-05T23:48:53.410</StatusChangeDate>
      </MLSInformation>
      <GeographicData>
        <Latitude>11.111111</Latitude>
        <Longitude>-111.111111</Longitude>
        <County>Pierce</County>
      </GeographicData>
      <SchoolData>
        <SchoolDistrict>Puyallup</SchoolDistrict>
      </SchoolData>
      <View>Territorial</View>
    </Listing>
    <YearBuilt>1997</YearBuilt>
    <InteriorFeatures>Bath Off Master,Dbl Pane/Storm Windw</InteriorFeatures>
    <Occupant>
      <Name>Vacant</Name>
    </Occupant>
    <WaterFront/>
    <Roof>Composition</Roof>
    <Exterior>Brick,Cement Planked,Wood,Wood Products</
</ResidentialProperty>

当我跑:

ResidentialProperty <- xmlToDataFrame(nodes=getNodeSet(doc,"//ResidentialProperty"))

父节点中子节点的值被压缩为:

11111111thAvenue CtWA2015-07-05T23:48:53.41011.111111-111.111111PiercePuyallupTerritorial

如果我向下移动一个节点,则会发生同样的事情:

11111111thAvenue CtWA

子节点的值全部粘贴在一起.

我也试过一种有点工作的蛮力方法:

StreetAddress <- xmlToDataFrame(nodes=getNodeSet(doc,"//StreetAddress"))
MLSInformation <- xmlToDataFrame(nodes=getNodeSet(doc,"//MLSInformation"))
GeographicData <- xmlToDataFrame(nodes=getNodeSet(doc,"//GeographicData"))
SchoolData <- xmlToDataFrame(nodes=getNodeSet(doc,"//SchoolData"))
YearBuilt <- xmlToDataFrame(nodes=getNodeSet(doc,"//YearBuilt"))
InteriorFeatures <- xmlToDataFrame(nodes=getNodeSet(doc,"//InteriorFeatures"))
Occupant <- xmlToDataFrame(nodes=getNodeSet(doc,"//Occupant"))
Roof <- xmlToDataFrame(nodes=getNodeSet(doc,"//Roof"))
Exterior <- xmlToDataFrame(nodes=getNodeSet(doc,"//Exterior"))
df <- cbind(StreetAddress, MLSInformation, GeographicData, SchoolData, YearBuilt, InteriorFeatures, Occupant, Roof, Exterior)

但有些列名不符合预期:

> colnames(df)
 [1] "StreetNumber"     "StreetName"       "StreetSuffix"     "StateOrProvince"  "ListingStatus"   
 [6] "StatusChangeDate" "Latitude"         "Longitude"        "County"           "SchoolDistrict"  
[11] "text"             "text"             "Name"             "text"             "text"    

colnames[11,12,14,15]应该"YearBuilt", "InteriorFeatures", "Roof", and "Exterior"分别.(旁注 - 为什么会这样？)

我试图找到一种方法将每个原子值排序到数据框的适当列中,列名称是节点的名称,甚至在嵌套的子节点中也是如此.此外,我的数据可能会随着时间的推移而发生变化,所以我正在寻找一种符合数据的动态函数,如果可能的话会产生预期的结果.

我想这是一个有点常见的XML架构(带有嵌套子层的层),所以我很惊讶没有找到关于这个主题的太多信息,尽管我可能只是在我的搜索中使用了错误的术语.我的猜测有一个简单的答案.你有什么建议吗？

Answer 1

考虑xml保留您的示例字符串,这是具有不同数量项目的住宅物业的另一种策略:

library(XML)
library(plyr) 
# xml <- '<ResidentialProperty>........'
doc <- xmlParse(xml, asText =  TRUE)
df <- do.call(rbind.fill, lapply(doc['//ResidentialProperty'], function(x) { 
  names <- xpathSApply(x, './/.', xmlName) 
  names <- names[which(names == "text") - 1]
  values <- xpathSApply(x, ".//text()", xmlValue)
  return(as.data.frame(t(setNames(values, names)), stringsAsFactors = FALSE))
}))
df
#   StreetNumber StreetName StreetSuffix StateOrProvince        StatusChangeDate  Latitude   Longitude County SchoolDistrict        View YearBuilt                     InteriorFeatures   Name        Roof                                Exterior
# 1        11111      111th    Avenue Ct              WA 2015-07-05T23:48:53.410 11.111111 -111.111111 Pierce       Puyallup Territorial      1997 Bath Off Master,Dbl Pane/Storm Windw Vacant Composition Brick,Cement Planked,Wood,Wood Products