Since tibbles add their class attributes first, you could use: tb <- tibble(a = 5) inherits(tb, "data.frame", which = TRUE) == 1
if "tb" is a data frame (only), TRUE is returned, for tibble FALSE. You could then coerce to data frame: as.data.frame(tb) -----Ursprüngliche Nachricht----- Von: R-package-devel [mailto:r-package-devel-boun...@r-project.org] Im Auftrag von Göran Broström Gesendet: Dienstag, 26. September 2017 12:09 An: r-package-devel@r-project.org Betreff: Re: [R-pkg-devel] tibbles are not data frames On 2017-09-26 11:56, Gábor Csárdi wrote: > On Tue, Sep 26, 2017 at 10:35 AM, Joris Meys <joris.m...@ugent.be> wrote: >> I don't like the dropping of dimensions either. That doesn't change >> the fact that a tibble reacts different from a data.frame. So tibbles >> do not inherit correctly from the class data.frame, and it can thus >> be argued that it's against OOP paradigms to pretend tibbles inherit >> from the class data.frame. > > I have yet to see an OOP system in which a subclass cannot override > the methods of its superclass. Not only is this in line with OOP > paradigms, it is actually one of the essential OOP features. > > To be more constructive, if you have a function that only works with > data frame inputs, then it is good practice to check that the supplied > input is indeed a data frame. This is independent of tibbles. It is not. I check input for being a data frame, but tibbles pass that test. That's the essence of the problem. > In practice it seems to me that an easy fix is to just call > as.data.frame on the input. This should either convert it to a data > frame, or throw an error. Sure, but I still need to rewrite the package. Görn > For tibbles it > drops the tbl* classes. > > Gabor > >> Defensive coding techniques would check if it's a tibble and return >> an error saying a data.frame is expected. Unless tibbles inherit >> correctly from data.frame. >> >> I have nothing against tibbles. But calling them "data.frame" raises >> expectations that can't be fulfilled. > > [...] > > ______________________________________________ > R-package-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-package-devel > ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel -- _____________________________________________________________________ Universitätsklinikum Hamburg-Eppendorf; Körperschaft des öffentlichen Rechts; Gerichtsstand: Hamburg | www.uke.de Vorstandsmitglieder: Prof. Dr. Burkhard Göke (Vorsitzender), Prof. Dr. Dr. Uwe Koch-Gromus, Joachim Prölß, Martina Saurin (komm.) _____________________________________________________________________ SAVE PAPER - THINK BEFORE PRINTING ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel
