r - Pivot wider produces nested object

Question

This is regarding latest tidyr release. I am trying pivot_wider & pivot_longer function from library(tidyr) (Update 1.0.0)

I was trying to obtain normal iris dataset when I run below but instead I get nested sort of 3X5 dimension tibble, not sure whats happening (I read https://tidyr.tidyverse.org/articles/pivot.html) but still not sure how to avoid this

library(tidyr)
iris %>% pivot_longer(-Species,values_to = "count") %>% 
pivot_wider(names_from = name, values_from = count)

Expected Output: Normal Iris dataset (150 X 5 dimension)

Edit: I read below that if I wrap around unnest() I get expected output. I am not able to understand why to unnest it when we did not nest it anywhere. Any basic help would be appreciated. Want to understand the concept of what went wrong.

Answer 1

As I learnt from Akrun & other helpful friends & post (Not a bug or anything)

spread(., name, count) throws an error because we have multiple rows for each species x name. pivot_wider does a better job by providing a list-columns instead. If we add unique ID to each row then it works fine.

library(tidyverse)

iris %>%
  rowid_to_column() %>% 
  pivot_longer(-c(rowid, Species), values_to = "count") %>%
  pivot_wider(names_from = name, values_from = count) %>% 
  select(-rowid)