get corrupts data.table object with a list column #1212
Description
Regarding this post, consider
require(data.table)
set.seed(123)
dt <- data.table(a=c("abc", "def", "ghi"), b=runif(3))
dt[, c:=list(list(data.table(d=runif(1), e=runif(1))))]
dt
# a b c
#1: abc 0.2875775 <data.table>
#2: def 0.7883051 <data.table>
#3: ghi 0.4089769 <data.table>
dt[, get("c")] ## <<-- not sure if print bug
# Error in FUN(X[[1L]], ...) :
# Invalid column: it has dimensions. Can't format it. If it's the result of data.table(table()), use as.data.table(table()) instead.
dt ## <<- why isn't this being printed?
# Error in FUN(X[[1L]], ...) :
# Invalid column: it has dimensions. Can't format it. If it's the result of data.table(table()), use as.data.table(table()) instead.
Interestingly, this still works:
rbindlist(dt[, get(var)])
# V1 V2
#1: 0.8830174 0.9404673
#2: 0.8830174 0.9404673
#3: 0.8830174 0.9404673Another scenario
set.seed(123)
dt <- data.table(a=c("abc", "def", "ghi"), b=runif(3))
dt[, c:=list(list(data.table(d=runif(1), e=runif(1))))]
var <- "c"
rbindlist(dt[[var]])
## d e
## 1: 0.8830174 0.9404673
## 2: 0.8830174 0.9404673
## 3: 0.8830174 0.9404673
rbindlist(dt[, get(var)])
## V1 V2
## 1: 0.8830174 0.9404673
## 2: 0.8830174 0.9404673
## 3: 0.8830174 0.9404673
rbindlist(dt[[var]])
## V1 V2 ## <<-- what happened to the column names?
## 1: 0.8830174 0.9404673
## 2: 0.8830174 0.9404673
## 3: 0.8830174 0.9404673Seems like column names were lost