Problems with PIP

[AlanTJohnstone]

I put this here so other people can find it.
I, like I suspect many other people uploaded the Anaconda distribution of Python as the easiest option to read the book. I already had a version of Python. I am running Windows 7.
All went well and everything worked until I tried to install filterpy on to my original Python setup.
Of course PIP was now “pointing” at the Anaconda version and despite Googling and asking a question on Stackoverflow I still do not know how this works and how you change it.
I had a rather old version of 2.7 so I decided to upgrade it (to 2.7.10) so I knew for certain that it had PIP installed. That worked but now I could not get at the notebook by typing “ipython notebook” as it now looks at the 2.7.10 version for what it needs.
My next great idea to sort this was to try and use pip2.7 and pip3.4 by reloading Anaconda but installing 3.4 rather than the 2.7 version that is the default. Pip2.7 works but there does not seem to be a version pip3.4 or at least I keep getting a response that the command is not recognized.
You might think that the pip would point to the latest installed version ie the Anaconda but for some unknown reason it still pointed to the 2.7.10 version. I therefore could not install filterpy in the Anaconda version.
The solution to all this is that I found that in the Anaconda folder there is an Anaconda Command Prompt which I got to from the Start Menu. Working in that pip works and finds the Anaconda version of Python and you can do ipython notebook although I now find the simplest way to start is to use the Anaconda graphical start up, choose ipython and navigate to the directory. Typing in that long directory name is a pain.
Why do I keep two versions of Python? Eell partly because I am an old foggy and have not yet got used to programming with iPython but also because my robot has a small Rpi in charge and I want to have a version the same as is on that.