IPython console in spyder extremely slow in Anaconda

Question

I’m trying Anaconda/Spyder after using the standard python installation/IDLE
for several years. The console (and variable explorer) becomes progressively
slower during each work session, with every script and interactive command
that I run. Eventually it takes minutes to get a response to simple commands
like print, and then it stops responding completely and I shut it down. It’s
pretty disruptive to my work.

Mac OSX 10.13.6

conda version : 4.5.11
conda-build version : 3.15.1
python version : 3.7.0.final.0

qt 5.9.6
spyder 3.3.1 
ipython 7.1.1

I do use matplotlib frequently. Whenever possible I use plt.ioff() at the
beginning of a script and/or plt.close(‘all’) at the end. Turning off
matplotlib support completely in preferences doesn’t help and it’s not a
permanent fix anyway. Python is not using anywhere near all my CPU or RAM.

Answer 1

So this is not a totally satisfying solution but it seems to be a reasonable
temporary fix. If you downgrade your spyder version to 3.1.X you will be able
to use the python console rather than the Ipython console, and this seems to
work for me. To do this just run:

conda install spyder=3.1

in the terminal while your environment of choice is active. This is not ideal,
because the developers removed the python console for a specific reason as
mentioned in this question, How to add python console in
spyder. Additionally downgrading this much may have unforeseen
effects on other packages your code uses and may cause other issues but so far
this is the only solution I was able to come up with.