This is a delicate balance. The crucial part (which you didn't mention)
is that this only happens if you add a column by df[, "c"] <- value ; if
you replace the contents of a column then attributes are preserved.
Clearly some attributes like names are invalidated when you extend a list,
and ot
Folks:
Problem: [<-.data,frame() is losing attributes under certain curcumstances
shown below.
I think this is a bug, at least in documentation, as I was unable to find
explicit documentation of the behavior. Indeed, the only documentation I
found told me attributes are preserved. Here is a de
