Remove empty elements from list with character(0)

Question

How can I remove empty elements from a list that contain zero length pairlist as character(0), integer(0) etc...

list2
# $`hsa:7476         


        

Answer 1

Funny enough, none of the many solutions above remove the empty/blank character string: "". But the trivial solution is not easily found: L[L != ""].

To summarize, here are some various ways to remove unwanted items from an array list.

# Our Example List:
L <- list(1:3, "foo", "", character(0), integer(0))

# 1. Using the *purrr* package:
library(purrr)
compact(L)

# 2. Using the *Filter* function:
Filter(length, L)

# 3. Using *lengths* in a sub-array specification:
L[lengths(L) > 0]

# 4. Using *lapply* (with *length*) in a sub-array specification:
L[lapply(L,length)>0]

# 5. Using a sub-array specification:
L[L != ""]

# 6. Combine (3) & (5)
L[lengths(L) > 0 & L != ""]