This is an interesting problem faced by most of the readers using "How to Think Like a Computer Scientist : Learning with Python", when they reach 4th chapter.
Now to install GASP, you need to check whether you have python installed on your machine.
Assumption: I am going to assume that you are using Mac.
Type the following command on your terminal,
`$ python -V`
{If your system has python installed on it, you will get an answer like Python 2.7.1 ( if the version is 2.7.1).}
Once you have python available on your system, you should install PyObjC.
An easy way out is to type on to your terminal prompt,
`$ easy_install pyobjc==2.2`
{this will install the version 2.2}
Next step is to install pygame package , you can do this in two ways either by downloading the .dmg file or using "homebrew". I prefer the second method.
to install pygame package using "brew" you have to install mercurial first. It's a simple procedure, just type in
$ brew install mercurial
Then type in the following commands,
$ brew install sdl sdl_image sdl_mixer sdl_ttf smpeg portmidi
$ sudo pip install hg+http://bitbucket.org/pygame/pygame
Next step is to install GASP. Download gasp from https://launchpad.net/gasp-core/+download
Extract the .tar file, you will get a folder structure. Our aim is to copy the folder named "gasp" to the Systems Library folder. To check which folder or version of python is used and to know their correct path type in the following command on terminal.
$ python -c 'import sys, pprint; pprint.pprint(sys.path)'
generally it will print a path similar to '/Library/Python/2.7/site-packages' , you can notice this either as the last line or the second last line of the output that above commands generate.
Copy the gasp folder to the site-packages folder,
$ sudo cp -R ~/Desktop/python-gasp-0.1.1/gasp/ /Library/Python/2.7/site-packages/gasp
This should copy all the required files to the location specified as the second argument.
Now go to terminal and type
$ python
>>> import gasp
If everything goes fine, you will not get any error or any messages.
PS: Ensure that in your site-packages directory there are no duplicate copies of pygame/gasp. In case of duplicates, it may throw lots of tantrums. Also, if any of the steps go wrong you may get error "import cairo" some 25th or 26th line on base.py in gasp package.In that event, please clean up your site packages directory by removing pygame and gasp and re-install them, that should solve it.
Also while installing mercurial you may get some warning related to Certificates. You can solve them by typing in following commands,
$ openssl req -new -x509 -extensions v3_ca -keyout /dev/null -out dummycert.pem -days 3650
$ sudo cp dummycert.pem /etc/hg-dummy-cert.pem
$ cd ~
$ nano .hgrc
{ This will open up an empty .hgrc file }
Type in the following
[web]
cacerts = /etc/hg-dummy-cert.pem
save the above 2 lines by pressing ctrl+ o
exit nano by pressing ctrl + x
Thats it. This should solve your problems with GASP installation and enjoy the book " How to Think Like a Computer Scientist" it's a wonderful introduction to the world of computing.
