[R] Convert a list with NULL to a dataframe with NA

[Mohammad Tanvir Ahamed]

Hi, 

I have a list like below. 

OB1 <- structure(list(aa0 = NULL, 
aa1 = structure("23403", .Names = "BB10"), 
aa2 = structure("54904", .Names = "BB20"), 
aa3 = structure("22897", .Names = "BB30"), 
aa4 = structure("3751", .Names = "BB40"), 
aa5 = NULL, 
aa6 = structure("3679", .Names = "BB50"), 
aa7 = structure("440193", .Names = "BB60"), 
aa8 = structure("23144", .Names = "BB70"), 
aa9 = structure("84667", .Names = "BB80"), 
aa10 = structure("130540", .Names = "BB90")), 
.Names = c("aa0", "aa1", "aa2", "aa3", 
"aa4", "aa5", "aa6", "aa7", 
"aa8", "aa9", "aa10"))

I am expecting an output like below
OB2 <- structure(list(V1 = structure(c(3L, 5L, 8L, 1L, 4L, 2L, 10L, 
7L, 9L, 11L, 6L), .Label = c("aa3", "aa5", "aa0", 
"aa4", "aa1", "aa10", "aa7", "aa2", 
"aa8", "aa6", "aa9"), class = "factor"), 
id = structure(c(NA, 4L, 8L, 2L, 6L, NA, 5L, 7L, 3L, 9L, 
1L), .Label = c("130540", "22897", "23144", "23403", "3679", 
"3751", "440193", "54904", "84667"), class = "factor"), nam = structure(c(NA, 
4L, 8L, 3L, 7L, NA, 6L, 2L, 9L, 5L, 1L), .Label = c("BB90", 
"BB60", "BB30", "BB10", "BB80", "BB50", "BB40", 
"BB20", "BB70"), class = "factor")), .Names = c("V1", 
"id", "nam"), row.names = c(NA, -11L), class = "data.frame")

Problems :
1. Get OB1 to OB2
2. Get OB2 to OB1

I  will be great-full if anyone can share idea how to solve the problem .
Thanks in advance !!



 
Tanvir Ahamed 
Göteborg, Sweden  |  mashranga at yahoo.com