其中“[[1]][-1,]”是什么意思？

install.packages('rvest')
library(rvest)
library(magrittr)
url <- paste0('http://vip.stock.finance.sina.com.cn/q/go.php/vFinanceAnalyze/',
'kind/profit/index.phtml')
url
web <- read_html(url)
web
xpath <- '//table[@class="list_table"]'
web_table <- web %>%html_nodes(xpath=xpath)%>%html_table()
web_table[[1]][-1,]