从函数中删除 .GlobalEnv 中的对象

Question

我想创建一个函数( CleanEnvir )，它基本上调用 remove/rm 并从 .GlobalEnv 中删除某些对象.

  CleanEnvir <- function(pattern = "tmp"){
      rm(list = ls()[grep("tmp", ls())], envir = globalenv())
  }

  keep <- 1
  tmp.to.be.removed <- 0
  ls()

  ## does not work
  CleanEnvir()
  ls()

  ## does work
  rm(list = ls()[grep("tmp", ls())], envir = globalenv())
  ls()

Answer 1

ls()需要看在正确的地方。默认情况下，它查看当前帧，即函数 CleanEnvir 的帧。在你的情况下，因此只找到 "pattern"在你的原文中。

CleanEnvir <- function(pattern = "tmp") {
    objs <- ls(pos = ".GlobalEnv")
    rm(list = objs[grep("tmp", objs)], pos = ".GlobalEnv")
}

这使:

> CleanEnvir <- function(pattern = "tmp") {
+     objs <- ls(pos = ".GlobalEnv")
+     rm(list = objs[grep("tmp", objs)], pos = ".GlobalEnv")
+ }
> ls()
[1] "CleanEnvir"        "foo"               "keep"             
[4] "tmp.to.be.removed"
> CleanEnvir()
> ls()
[1] "CleanEnvir" "foo"        "keep"