# Hi
#
# Last updated: Feb 27 2016
#
# These notes are for installing "modern" python (3.4) on ubuntu 12.04
# This is explicity for people who followed the well-meaning advice at
# http://askubuntu.com/questions/412178/how-to-install-pip-for-python-3-in-ubuntu-12-04-lts/412179#comment1100126_412179
# which might have worked when written but as of Feb 2016, really 
# breaks a python install.
#
# Note that this could *become* a script with a little bit of editing but
# currently every command is wrapped in a function which intentionally is not
# invoked. 
# 
# Read the comments before you blindly run them on your system.  Some of them
# intentionally "burn the village" and state as much.
#

dump_python() {
  # First dump pip3
  easy_install3 -m pip

  # This still leaves things around so we have to dump them manually
  # It's easy_install, not easy_uninstall
  #
  # we dump them all because they're all currently broken.
  rm /usr/local/bin/pip3*

  # Now we dump the egg manually.  We presume 
  # All the pips here are busted or not supported (100% true).
  rm -fr /usr/local/lib/python3.2/dist-packages/pip-*

  # And now we dump all variations of python3 so as
  # not to mess things up again.  This will make the
  # screen look scary but if you look at the list, it's
  # just python3.  the purge gets rid of things that suggest
  # a python3.2 should exist somewhere. It shouldn't.
  #
  # This will also remove things like python3.3 and 3.4
  # which it ostensibly looks like it shouldn't (it should,
  # that's another discussion). This is what we WANT because
  # we don't preferably want a bunch of 3.x versions lying
  # around since there apparently are intentional breaks
  # for 3.x versions of python's core utils.  
  #
  # It's best to be (as of Feb 2016) in 3.4 or higher.
  #
  # Note: If you don't do the above dump of pip3 first, then
  # you will be stucks with those files lurking around without
  # the python 3.2 infrastructure of easy_install to remove them
  # in the way listed above
  apt-get purge python3.2\*
}

get_python34() {
  # Now that we've unhosed our system of broken python3 we need to
  # redo this with python 3.4+ which will not break with pip8
  # see https://www.reddit.com/r/Python/comments/20xims/is_there_an_easy_way_to_install_python_34_on/
  add-apt-repository ppa:fkrull/deadsnakes
  apt-get update
  apt-get install python3.4

  # You probably also need these libraries for building packages
  # such as pycurl or lxml
  apt-get install python3.4-dev libpython3.4-dev

  # Make the interpreter of python3 have a symlink
  # if things didn't get set up this way.  It really
  # shouldn't be there since we so agressively reset
  # ourselves but safety is safety.
  [ -e /usr/bin/python3 ] || ln -s /usr/bin/python3.4 /usr/bin/python3
}

get_pip() {
  # Although python3.4 "ships with pip" the PPA doesn't.
  # So we need to do this ourselves.
  # Look at http://stackoverflow.com/questions/11268501/how-to-use-pip-with-python-3-x-alongside-python-2-x
  curl https://bootstrap.pypa.io/get-pip.py > /tmp/get-pip.py
  python3.4 /tmp/get-pip.py
  rm -f /tmp/get-pip.py

  # This will place pip8 on the system for 3.4 and
  # upgrade it for 2.7 if you have it sitting around
  # still
  pip -U pip
}

make_pip_wrapper() {
  # Alright we are so close. There's no pip3 anymore if you notice.
  # That's becaues the new *built-in* method works by invoking pip
  # within the version of python you want like this:
  #
  # python3.4 -m pip install
  #
  # "This is bunk" you say. "All my legacy shit will break".
  # Indeed.  Let's just write a wrapper then.
  [ -e /usr/local/bin/pip3 ] && mv /usr/local/bin/pip3 /usr/local/bin/pip3.old
  echo 'python3.4 -m pip $*' > /usr/local/bin/pip3
  chmod +x /usr/local/bin/pip3
}