疫情地图DIY—省市地图

    前面两期，我们分别介绍了疫情地图DIY—数据获取和疫情地图DIY—全国地图。可能有人更关心湖北省的疫情情况，毕竟这次疫情首先发生在武汉，并且周围的黄冈市和孝感市都是重灾区。那么今天我们就来画各省市的疫情地图。

    第一步还是获取数据，在疫情地图DIY—数据获取一文中，我们讲过了如何获取省份的疫情数据。实际上，抓取的网页里面已经包含了城市的数据，只是我们没有用正则表达式提取而已。那么今天我们就先来获取每个城市的疫情数据。我还是用了R和Perl两种方法来实现。

Perl获取城市疫情数据：

#!/usr/bin/perl -wuse LWP::Simple qw(get);
use utf8;use Encode;#获取丁香园网页信息$content=get("https://3g.dxy.cn/newh5/view/pneumonia");#疫情信息写入到2019-ncov_cities.csv中open OUT,">2019-ncov_cities.csv";#表头信息print OUT "province,city,confirmed,suspected,cured,dead\n";#利用正则表达式提取省份名称while($content=~/"provinceName":"([^"]+)","provinceShortName":"([^"]+)","confirmedCount":(\d+),"suspectedCount":(\d+),"curedCount":(\d+),"deadCount":(\d+),".*?"cities":\[(.*?)\]}/sg){ $cities=$7; $province=$1;#利用正则表达式提取城市名称，确诊，死亡和治愈的人数 while($cities=~/"cityName":"([^"]+)","confirmedCount":(\d+),"suspectedCount":(\d+),"curedCount":(\d+),"deadCount":(\d+)/sg){$a="市";#城市信息连同省份名字一起输出#在城市名称后面加一个'市'，网页上获取的城市名称为'武汉’，没有“市”$line="$province,$1$a,$2,$3,$4,$5"; $line=encode("gb2312",$line);print OUT "$line\n";}}


打开2019-ncov_cities.csv查看城市信息

R获取城市疫情数据：

#从丁香园抓取网页信息web_page <- readLines("https://3g.dxy.cn/newh5/view/pneumonia")#获取包含疫情数据的行info_row<- web_page[grep("getAreaStat", web_page)]info_row=sub('.*<script id="getAreaStat">(.*?)</script>.*',"\\1",perl=T,info_row)
#定义提取城市疫情数据的函数extractextract=function(x,province){a=sub('.*"cityName":"([^"]+)","confirmedCount":(\\d+),"suspectedCount":(\\d+),"curedCount":(\\d+),"deadCount":(\\d+).*', "\\1:\\2:\\3:\\4:\\5", x ,perl=TRUE)c(province,unlist(strsplit(a,":")))}
#获取城市疫情数据city=c()#将疫情数据分成34个省份provinces=strsplit(info_row,"]},",fixed=T)#从每个省份提取该省份中城市疫情的数据for(i in provinces[[1]]){ province=sub('.*"provinceName":"([^"]+)","provinceShortName":"([^"]+)".*', "\\2", i ,perl=TRUE) if(length(grep('.*"cityName":"([^"]+)","confirmedCount":(\\d+),"suspectedCount":(\\d+),"curedCount":(\\d+),"deadCount":(\\d+).*',i))>0){ cities=strsplit(i,'},{',fixed=T) b=do.call(rbind,lapply(cities[[1]],extract,province=province)) city=rbind(city,b)}}
city=as.data.frame(city)#定义表头names(city)=c("province","city","confirmed","suspected","cured","dead")city$province=iconv(city$province,"UTF-8",'GB2312')#在城市名称后面加一个'市'，网页上获取的城市名称为'武汉’，没有“市”b="市"b=iconv(b,"UTF-8",'GB2312')city$city=paste(iconv(as.character(city$city),"UTF-8",'GB2312'),b,sep="")#将数据写入到csv文件中write.csv(file="city.csv",city,quote=F,row.names=F)


打开city.csv查看城市疫情数据

    下面还是使用疫情地图DIY—全国地图里面用到的R包REmap来画各省市疫情地图，这里以湖北省为例。