_ipython_display_ not ignored in the REPL

[aulemahal]

In the docs, it says, about _ipython_display_, that "This method is ignored in the REPL."
However, when I open a REPL and type the following:

In [1]: class A:
   ...:     def _ipython_display_(self):
   ...:         print('woups')
   ...: 

In [2]: A()

I get:

Out[4]: woups

Thus, it is not doing what the doc says. Is the doc wrong? (I expected something like <__main__.A at 0x7f4ad9bdab20>)

This looks inoffensive here, but my issue came from an object defined in some library that uses the _ipython_display_ method to display a HTML repr, so I only see <IPython.core.display.HTML object>. This object does have a correct __repr__ method implemented, so I expected to see that, as it is the case in the basic python repl.

Thanks!

I tried this with IPython 8.1.1 and 8.3.0, both gave the same result.
I tried with 7.22 and I got what I expected (_ipython_display_ was ignored).

[MrMino]

I'm going to consider it as a bug, cause it seems to be in the documentation for a reason: 56bafa1. That said, it's not entirely clear to me why wouldn't we want the REPL to use it. @Carreau? @bollwyvl? @takluyver?

[Carreau]

Because there is not reason for a shell to not play sounds, or to display images (it just need to be implemented), iTerm2 has it's own protocol and many terminal emulators support sixel.

IPython CLI could perfectly for example display an svg on MacOS by opening quicklook.

For that we need to send all the mimetype and sometime call _ipython_display_.

[MrMino]

I'm guessing then, that "This method is ignored in the REPL" part of the documentation is something we should get rid of.

[agoose77]

Just ran into this! #13851