[R] converting a list to a data.frame

Hello, I have a list with n numerical components of different length (3, 4 or 5 values in each component of the list); I need to export this as a text file where each component of the list will be a row and where missing values should fill in the blanks due to the different lengths of the

[R] Merge: how can I keep discarded values?

Good morning, I am merging two datasets and I would like to save the non-matching rows in a separate file. The problem is how to retrieve the non-matching rows in R. Example: DATASET A code nomi A1 Franco A2 Mario A3 Andrea A4 Sandro A5 Luca DATASET B code