使用
stringr
包和 regex
你可能会实现你正在寻找的东西,但你需要知道所有的可能性。也许如果您想要的内容和烦人的信息之间只有下划线,您可以使用 str_split
和“_”作为模式参数来解决您的问题。
library(stringr)
df <- data.frame(chromosome = c("chr6_GL000253v2_alt", "chr6_GL000254v2_alt",
"chr6_GL000255v2_alt", "chr6_GL000256v2_alt", "chr4", "chr11",
"chr8", "chr12", "chr2", "chr12", "chr4", "chr6", "chr15", "chr4",
"chr2"))
df$chromosome_fixed=str_split(df$chromosome,"_",simplify = T)[,1]
随包解决方案
data.table
:
代表
library(data.table)
library(stringr)
DT[, Chr_ID := lapply(.SD, str_extract,"(?<=^chr)\\d+"), .SDcols = "chromosome"]
DT
#> chromosome Chr_ID
#> 1: chr6_GL000253v2_alt 6
#> 2: chr6_GL000254v2_alt 6
#> 3: chr6_GL000255v2_alt 6
#> 4: chr6_GL000256v2_alt 6
#> 5: chr4 4
#> 6: chr11 11
#> 7: chr8 8
#> 8: chr12 12
#> 9: chr2 2
#> 10: chr12 12
#> 11: chr4 4
#> 12: chr6 6
#> 13: chr15 15
#> 14: chr4 4
#> 15: chr2 2
DT <- data.table(chromosome = c("chr6_GL000253v2_alt", "chr6_GL000254v2_alt",
"chr6_GL000255v2_alt", "chr6_GL000256v2_alt", "chr4", "chr11",
"chr8", "chr12", "chr2", "chr12", "chr4", "chr6", "chr15", "chr4",
"chr2"))
DT
#> chromosome
#> 1: chr6_GL000253v2_alt
#> 2: chr6_GL000254v2_alt
#> 3: chr6_GL000255v2_alt
#> 4: chr6_GL000256v2_alt
#> 5: chr4
#> 6: chr11
#> 7: chr8
#> 8: chr12
#> 9: chr2
#> 10: chr12
#> 11: chr4
#> 12: chr6
#> 13: chr15
#> 14: chr4
#> 15: chr2
由 reprex 包于 2021 年 10 月 12 日创建(v2.0.1)