Python comes installed with Mac OSX and most GNU/Linux systems, but it does not come with Windows 7. It is free software, however, and installation on Windows 7 is quick and easy.
.msi installer.Install for all users(the default option) and click the Next > button.
C:\Python32\) as the destination
directory and click Next > button again.Customize Python 3.2.3dialog, just click Next > again.
The installation process creates a Python 3.2 section under
Start Menu -> All Programs. Click on this to expand it, then
click IDLE (Python GUI) to launch the Python Integrated
Development program (IDLE).