如何在R语言字符向量中提取两个指定字符串间的内容

嘿，这事儿不难，咱们可以通过定位两个标记的索引，然后提取中间的元素来实现。下面是具体的R代码实现：

首先先把你的向量定义好：

FINDINGS <- c("FD_BarrettDetail", "The segment looks flat.", "Prague score C0M3", 
              "It is x cm in length.", "This is an ultra-short segment.", 
              "FD_BarrettDetail1_Benign", "The segment looks flat.", "No nodularity is present.", 
              "It is a long segment.", "Some areas of vascular abnormalities are seen.", 
              "The pit pattern is normal.")

接下来，找到两个分隔标记的位置：

# 找到起始标记的索引，加1跳过标记本身
start_idx <- which(FINDINGS == "FD_BarrettDetail") + 1
# 找到结束标记的索引，减1跳过标记本身
end_idx <- which(FINDINGS == "FD_BarrettDetail1_Benign") - 1

然后提取中间的元素：

result <- FINDINGS[start_idx:end_idx]

运行这段代码后，result就是你要的目标结果啦，输出如下：

[1] "The segment looks flat."       "Prague score C0M3"             "It is x cm in length."         "This is an ultra-short segment."

如果你的向量里可能存在多个相同的标记，那可以用match()函数确保只取第一个匹配的位置，这样更稳妥：

start_idx <- match("FD_BarrettDetail", FINDINGS) + 1
end_idx <- match("FD_BarrettDetail1_Benign", FINDINGS) - 1

内容的提问来源于stack exchange，提问作者Sebastian Zeki