问题描述
我有一组文件名,例如:
I have a set of file names like:
filelist <- c("filea-10.txt", "fileb-2.txt", "filec-1.txt", "filed-5.txt", "filef-4.txt")
,我想根据-"后的数字过滤它们.
and I would like to filter them according to the number after "-".
例如,在python中,我可以使用排序函数的key
参数:
In python, for instance, I can use the key
parameter of the sorting function:
filelist <- ["filea-10.txt", "fileb-2.txt", "filec-1.txt", "filed-5.txt", "filef-4.txt"]
sorted(filelist, key=lambda(x): int(x.split("-")[1].split(".")[0]))
> ["filec-1.txt", "fileb-2.txt", "filef-4.txt", "filed-5.txt", "filea-10.txt"]
在R中,我正在玩strsplit
和lapply
,到目前为止还没有运气.
In R, I am playing with strsplit
and lapply
with no luck so far.
在R中使用哪种方法?
修改:文件名可以是很多东西,并且可以包含更多数字.唯一固定的模式是我要排序的数字在-"之后.另一个(真实的)示例:
Edit:File names can be many things and may include more numbers. The only fixed pattern is that the number I want to sort by is after the "-". Another (real) example:
c <- ("boards10017-51.mp4", "boards10065-66.mp4", "boards10071-81.mp4",
"boards10185-91.mp4", "boards10212-63.mp4", "boards1025-51.mp4",
"boards1026-71.mp4", "boards10309-89.mp4", "boards10310-68.mp4",
"boards10384-50.mp4", "boards10398-77.mp4", "boards10419-119.mp4",
"boards10421-85.mp4", "boards10444-87.mp4", "boards10451-60.mp4",
"boards10461-81.mp4", "boards10463-52.mp4", "boards10538-83.mp4",
"boards10575-62.mp4", "boards10577-249.mp4")"
推荐答案
我不确定文件名列表的实际复杂性,但是类似以下内容可能就足够了:
I'm not sure of the actual complexity of your list of file names, but something like the following might be sufficient:
filelist[order(as.numeric(gsub("[^0-9]+", "", filelist)))]
# [1] "filec-1.txt" "fileb-2.txt" "filef-4.txt" "filed-5.txt" "filea-10.txt"
考虑您的编辑,您可能需要将gsub
更改为以下内容:
Considering your edit, you may want to change the gsub
to something like:
gsub(".*-|\\..*", "", filelist)
同样,在没有更多文本情况的情况下,很难说这是否满足您的需求.
Again, without a few more text cases, it's hard to say whether this is sufficient for your needs.
示例:
x <- c("boards10017-51.mp4", "boards10065-66.mp4", "boards10071-81.mp4",
"boards10185-91.mp4", "boards10212-63.mp4", "boards1025-51.mp4",
"boards1026-71.mp4", "boards10309-89.mp4", "boards10310-68.mp4",
"boards10384-50.mp4", "boards10398-77.mp4", "boards10419-119.mp4",
"boards10421-85.mp4", "boards10444-87.mp4", "boards10451-60.mp4",
"boards10461-81.mp4", "boards10463-52.mp4", "boards10538-83.mp4",
"boards10575-62.mp4", "boards10577-249.mp4")
x[order(as.numeric(gsub(".*-|\\..*", "", x)))]
## [1] "boards10384-50.mp4" "boards10017-51.mp4" "boards1025-51.mp4"
## [4] "boards10463-52.mp4" "boards10451-60.mp4" "boards10575-62.mp4"
## [7] "boards10212-63.mp4" "boards10065-66.mp4" "boards10310-68.mp4"
## [10] "boards1026-71.mp4" "boards10398-77.mp4" "boards10071-81.mp4"
## [13] "boards10461-81.mp4" "boards10538-83.mp4" "boards10421-85.mp4"
## [16] "boards10444-87.mp4" "boards10309-89.mp4" "boards10185-91.mp4"
## [19] "boards10419-119.mp4" "boards10577-249.mp4"
这篇关于R根据子字符串对字符串排序的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!