[Help] I want to export a summary table of all of my dataset

General
3

Here is another approach. The lines where I load the data sets mtcars, iris and iris3 are only there to provide some objects for the reproducible example. You can write the object TBL as a csv or an Excel file.

library(tibble)
library(purrr)
M <- mtcars
I <- iris
I3 <- iris3 #not a data frame
DataNames <- ls()
GetInfo <- function(x) {
  Obj <- get(x)
  if (grepl("data.frame", class(Obj))) {
    Name <- x
    Obs <-  nrow(Obj)
    Vars <- ncol(Obj)
  } else {
    Name <-  x
    Obs <-  NA
    Vars <-  NA
  }
  tibble(Name = Name, Observations = Obs, Variables = Vars)
  
}
TBL <- map_dfr(DataNames, GetInfo )
TBL
#> # A tibble: 3 x 3
#>   Name  Observations Variables
#>   <chr>        <int>     <int>
#> 1 I              150         5
#> 2 I3              NA        NA
#> 3 M               32        11

Created on 2020-05-16 by the reprex package (v0.3.0)