emacs org-babel results unexpected output

Question

I'm using emacs 25.2.1 with spacemacs and scimax and trying to create a jupyter-like notebook. After some experimenting, I'm confused by the output I get from the :results output tag from the final src block:

#+name: OOP
#+BEGIN_SRC elisp :results silent :session OOP
  (pyvenv-activate "~/Desktop/py2_venv")
#+END_SRC

#+BEGIN_SRC ipython :session OOP :results silent
  class Dog():
      def __init__(self, breed, name, spots):
          self.breed = breed
          self.name = name

          #expect boolean true/false
          self.spots = spots
#+END_SRC   

#+BEGIN_SRC ipython :session OOP :results output 
  my_dog = Dog(breed='lab', name='Sammy', spots='False')
  print(type(my_dog))
  print(my_dog.breed)
  my_dog.name
  my_dog.spots
#+END_SRC

#+RESULTS:
**:RESULTS:
# Out[23]:
# output
<class '__main__.Dog'>
lab

# text/plain
: 'False'**
:END:

It's my understanding that all output should be displayed with the output option in session mode. Additionally I shouldn't need to use print(). I'm confused why my_dog.name is missing from output, but my_dog.spots is not. Any ideas what I'm missing?

Answer 1

:results output gives back the stdin, which will be the print output.

If you use :results value or :results value raw you will receive the last evaluation and not the side effect :

#+BEGIN_SRC ipython :session OOP :results value
 my_dog = Dog(breed='lab', name='Sammy', spots='False')
 print(type(my_dog))
 print(my_dog.breed)
 my_dog.name
 my_dog.spots
#+END_SRC

In order to get both evaluations you will need to type a bit more python.

Have a look at :

https://orgmode.org/worg/org-contrib/babel/languages/ob-doc-python.html

also the following answer in Emacs SE: https://emacs.stackexchange.com/a/45121/17548