将增量数字附加到列中的特定字符串

Question

我确定这是一些基本的东西，但我就是找不到合适的解决方案。我有一个很大的 df，看起来像：

Sample  cat
data1   124
data2   125
data3   126
Test1   Nice
Test2   Fluffy
Sample  Dog
data1   123
data2   124
data3   125
Test1   Good
Test2   Soft

我想将增量数字添加到第一列中的 Sample 值，这样我会得到以下输出：

Sample_1    cat
data1   124
data2   125
data3   126
Test1   Nice
Test2   Fluffy
Sample_2    Dog
data1   123
data2   124
data3   125
Test1   Good
Test2   Soft

我尝试了各种 gsub、grep、paste、paste0 组合，但都不满意。

例子

structure(list(V1 = c("Sample", "data1", "data2", "data3", "Test1", "Test2", "Sample", "data1", "data2", "data3", "Test1", "Test2"), V2 = structure(c(5L, 2L, 3L, 4L, 9L, 7L, 6L, 1L, 2L, 3L, 8L, 10L), .Label = c("123", "124", "125", "126", "cat", "Dog", "Fluffy", "Good", "Nice", "Soft"), class = "factor")), row.names = c(NA, -12L), class = "data.frame")

Answer 1

您可以使用 cumsum 来获取 Samples 和 paste 的数量，即

d1$V1[d1$V1 == 'Sample'] <- paste0(d1$V1[d1$V1 == 'Sample'], '_', unique(cumsum(d1$V1 == 'Sample')))

Answer 2

像这样的东西应该有用...

df2 <- df %>% 
  filter(str_detect(V1, "Sample")) %>% 
  mutate(V1 = ifelse(str_detect(V1, "Sample"), paste0("Sample_", row_number()), V1))

df <- df[-which(df$V1 == "Sample"),]


rbind(df2, df)

-布伦南

将增量数字附加到列中的特定字符串

Append incremental number to specific string in a column

r

paste

gsub