不确定如何分离我抓取的一列数据

Question

我从 espn 网站上抓取了奥尔巴尼女子篮球队的赛程表数据，win/loss 列的格式如下：W 77-70，这意味着奥尔巴尼以 77-70 获胜。我想将其分开，以便一栏显示奥尔巴尼得了多少分，以及对手得了多少分。

这是我的代码，不知道接下来要做什么：

library(rvest)
library(stringr)
library(tidyr)

w.url <- "http://www.espn.com/womens-college-basketball/team/schedule/_/id/399"
webpage <- read_html(w.url)

w_table <- html_nodes(webpage, 'table')
w <- html_table(w_table)[[1]]
head(w)

w <- w[-(1:2), ]
names(w) <- c("Date", "Opponent", "Score", "Record")
head(w)

Answer 1

您可以先使用grepl函数trim排除那些没有提供真实结果的行，然后使用正则表达式获取特定信息：

w <- w[grepl("-", w$Score),]

gsub("^([A-Z])([0-9]+)-([0-9]+).*", "\1,\2,\3", w$Score) %>% 
  strsplit(., split = ",") %>%
  lapply(function(x){
    data.frame( 
      result  = x[1],
      oponent = ifelse(x[1] == "L", x[2], x[3]),
      albany  = ifelse(x[1] == "W", x[2], x[3])
    )
  }) %>%
  do.call('rbind',.) %>% 
  cbind(w,.) -> w2

head(w2)
#         Date           Opponent  Score    Record result oponent albany
#3  Fri, Nov 9 @#22 South Florida L74-37 0-1 (0-0)      L      74     37
#4 Mon, Nov 12           @Cornell L48-34 0-2 (0-0)      L      48     34
#5 Wed, Nov 14        vsManhattan W60-54 1-2 (0-0)      W      54     60
#6 Sun, Nov 18           @Rutgers L65-39 1-3 (0-0)      L      65     39
#7 Wed, Nov 21          @Monmouth L64-56 1-4 (0-0)      L      64     56
#8 Sun, Nov 25       vsHoly Cross L56-50 1-5 (0-0)      L      56     50

Answer 2

我就是这样做的。基本上，根据奥尔巴尼是赢还是输，使用 sub 提取赢或输值。奥尔巴尼是赢还是输赢家列在第一位。所以ifelse函数是必须的。 “\1”捕获括号中的数字。

w<-w[1:24,]
w$Albany<-ifelse(substr(w$Score,1,1)=='W',sub('W(\d+)-\d+','\1',w$Score),sub('L\d+-(\d+)','\1',w$Score))
w$Opponent_Team<-ifelse(substr(w$Score,1,1)=='W',sub('W\d+-(\d+)','\1',w$Score),sub('L(\d+)-\d+','\1',w$Score))

head(w)
      Date           Opponent  Score    Record Albany Opponent_Team
3  Fri, Nov 9 @#22 South Florida L74-37 0-1 (0-0)     37            74
4 Mon, Nov 12           @Cornell L48-34 0-2 (0-0)     34            48
5 Wed, Nov 14        vsManhattan W60-54 1-2 (0-0)     60            54
6 Sun, Nov 18           @Rutgers L65-39 1-3 (0-0)     39            65
7 Wed, Nov 21          @Monmouth L64-56 1-4 (0-0)     56            64
8 Sun, Nov 25       vsHoly Cross L56-50 1-5 (0-0)     50            56




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不确定如何分离我抓取的一列数据

Not sure how to separate a column of data that I scraped

r

html-parsing

web-scraping

rvest