PyQtGraph does not really require any installation scripts. All that is needed is for the pyqtgraph folder to be placed someplace importable. Most people will prefer to simply place this folder within a larger project folder. If you want to make pyqtgraph available system-wide, use one of the methods listed below:
***Debian, Ubuntu, and similar Linux:** Download the .deb file linked at the top of the pyqtgraph web page or install using apt by putting "deb http://luke.campagnola.me/debian dev/" in your /etc/apt/sources.list file and install the python-pyqtgraph package.
***Arch Linux:** Looks like someone has posted unofficial packages for Arch (thanks windel). (https://aur.archlinux.org/packages.php?ID=62577)
***Windows:** Download and run the .exe installer file linked at the top of the pyqtgraph web page.
***From Source(including OSX):** Download the .tar.gz source package linked at the top of the pyqtgraph_ web page, extract its contents, and run "`python setup.py install`" from within the extracted directory.