Can I have my electric cake and eat it too? (Python mode question)

[Skip Montanaro]

I was annoyed that entering a colon at the end of a line in a Python buffer
didn't automatically reindent the line (say, entering a colon after typing
"else" didn't line it up with its matching "if"). After a little reading, I
figured out I needed to call (electric-indent-mode) in my python-mode-hook.
Done. Now, however, C-j (bound to electric-newline-and-maybe-indent) no
longer indents. The doc for that function says, "Insert a newline. If
`electric-indent-mode' is enabled, that's it..."

Is there no way to have my cake (colon reindents the current line) and eat
it too (C-j inserts a newline *and* reindents the line)? I've been
programming in Python for over 20 years (my how time flies). (re)Indenting
lines is a really common activity. Having it happen automatically only
about half the time seems suboptimal. If there was an
electric-newline-and-indent function, I could just bind it to C-j in my
python-mode-hook. It obviously won't be hard to write (just remove the mode
check), but maybe I'm missing some good reason why you wouldn't always want
to reindent after a newline while entering Python code.

My environment is currently Emacs 24.5.1 on RH Linux, using the Emacs which
apparently comes with Continuum Analytics' Anaconda distro.

Thx,

Skip Montanaro