如何基于条件向R数据框列追加分类文本？无需循环实现

实现代码 #

你可以通过如下两种无显式循环的方案实现需求，分类规则可灵活扩展：

方案1：tidyverse 实现（代码可读性更高）

# 加载依赖包
library(dplyr)
library(stringr)

# 构造原始数据
df <- data.frame(
  animals = c("monkey", "humpback whale", "river trout", "seagull"),
  categories = NA_character_
)

# 定义分类规则，后续新增分类只需往列表中添加元素即可
category_rules <- list(
  mammal = c("whale", "monkey", "dog"),
  swimming = c("whale", "trout", "dolphin")
)

# 执行分类匹配
df <- df %>%
  rowwise() %>%
  mutate(
    categories = {
      matched <- names(category_rules)[sapply(category_rules, \(rule) any(str_detect(animals, rule)))]
      ifelse(length(matched) > 0, paste(matched, collapse = ","), "")
    }
  ) %>%
  ungroup()

方案2：base R 实现（无需额外安装包）

# 构造原始数据
df <- data.frame(
  animals = c("monkey", "humpback whale", "river trout", "seagull"),
  categories = NA_character_
)

category_rules <- list(
  mammal = c("whale", "monkey", "dog"),
  swimming = c("whale", "trout", "dolphin")
)

# 执行分类匹配
df$categories <- sapply(df$animals, \(x) {
  matched <- names(category_rules)[sapply(category_rules, \(rule) any(grepl(rule, x)))]
  ifelse(length(matched) > 0, paste(matched, collapse = ","), "")
}, USE.NAMES = FALSE)

两种方案运行后得到的df都和你预期的输出结果完全一致。

内容的提问来源于stack exchange，提问作者szgfi