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andschar
andschar

Reputation: 3973

function to clean current workspace apart from some variables

How can I write a generic R function that cleans the current workspace apart from some self-defined variables? For sure, I can achieve this in a single script with the following code:

prj = '/path/to/project'
src = 'string'
data_to_clean = head(iris)
rm(list = ls()[ !ls() %in% c('prj', 'src') ] )
# only prj and src remain

However I want this to be a function, so that it's applicable for multiple scripts and I can change the variables which should not be cleaned, in one place. Is this possible?

Upvotes: 2

Views: 71

Answers (2)

Ramiro Magno
Ramiro Magno

Reputation: 3175

I think you want to remove the function itself. The important bit is to tell rm the environment where to remove these objects from:

clean_workspace <- function(not_to_be_removed, envir = globalenv()) {
  objs <- ls(envir = envir)
  rm(list = objs[ !objs %in% not_to_be_removed], envir = envir)
}

prj = '/path/to/project'
src = 'string'
data_to_clean = head(iris)
clean_workspace(c('prj', 'src'))
ls()
#> [1] "prj" "src"

Upvotes: 1

loki
loki

Reputation: 10350

In case you wrap this in a function, you have to keep in mind, that a function will create its own environment, when executed. Therefore, you need to specify the environment every time (in each ls as well as rm). You probably want to remove them from the .GlobalEnv. 

clean_workspace <- function(not_to_be_removed) {
  rm(list = 
    setdiff(ls(envir = .GlobalEnv), c("clean_workspace", not_to_be_removed)), 
    envir = .GlobalEnv)
}

prj = '/path/to/project'
src = 'string'
data_to_clean = head(iris)
clean_workspace(c('prj', 'src'))

In order not to remove the function itself, it should be added to the values not to be removed.

If you want to read more about environments, have a look a this overview.

Upvotes: 1

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