Whitespace string can't be replaced with NA in R

Question

I want to substitute whitespaces with NA. A simple way could be df[df == \"\"] <- NA, and that works for most of the cells of my data frame....but not for ev

Answer 1

I just spent some time trying to determine a method usable in a pipe.

Here is my method:

df <- df %>% 
    dplyr::mutate_all(funs(sub("^\\s*$", NA, .)))

Hope this helps the next searcher.

Answer 2

We need to use lapply instead of sapply as sapply returns a matrix instead of a list and this can create problems in the quotes.

df[1:10] <- lapply(df[1:10], trimws)

and another option if we have spaces like " " is to use gsub to replace those spaces to ""

df[1:10] <- lapply(df[,c(1:10)], function(x) gsub("^\\s+|\\s+$", "", x))

and then change the "" to NA

df[df == ""] <- NA

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Or instead of doing the two replacements, we can do this one go and change the class with type.convert

df[] <- lapply(df, function(x)
      type.convert(replace(x, grepl("^\\s*$", trimws(x)), NA), as.is = TRUE))

NOTE: We don't have to specify the column index when all the columns are looped