How do I merge dataframes contained in a meta dataframe?

Question

My tibble contains multiple dataframes as follows:

cntry	df
south_africa	8 variables
angola	8 variables
ghana	8 variables

Each sub-dataframe (i.e. one of the variables referred to above) is as follows:

date	growth	external_financing
2020-01-01	-1	0
2020-02-01	-1	1
2020-03-01	-2	1

How do I merge all the dataframes to have a column with the country to which that score relates? I would like a result as follows (clearly, some pivoting will also be required):

date	country	metric	score
2020-01-01	south_africa	growth	0
2020-02-01	south_africa	growth	1
2020-03-01	south_africa	growth	1
2020-01-01	south_africa	external_financing	0
2020-02-01	south_africa	external_financing	1
2020-03-01	south_africa	external_financing	1

And so on...with all the data in this long format.

Answer 1

You can try using unnest and pivot_longer -

library(dplyr)
library(tidyr)

data %>%
  unnest(df) %>%
  pivot_longer(cols = -c(cntry, date), 
               names_to = 'metric', values_to = 'score')