So I think I better write the answer here :)
And the answer is NO. Python is used in lots of places:
- Web Programming: Python is heavily used in Web Programming. There is a great CMS named Plone, developed in Python. There are also some good web frameworks. Also the Google Application Engine is developed using Python
- Desktop Computing: Python can be used to develop software for desktop. There are multiple ways to develop GUI for your python software. You can use Tkinter, wxPython etc.
- Distributed Computing: It's another field where Python is used effectively. Once I heard about the RIVER project (I forgot the link) which is developed using Python.
- Mobile Phone Programming: Yes, Python can be used in your mobile phones. Nokia developed PyS60 to run in Symbian S60 (series 60) phones. There is also a book available for PyS60 Mobile Python: Rapid prototyping of applications on the mobile platform (Symbian Press)
- Game Programming!: There is PyGame. So if you are really want to have some fun while coding, want to develop an interesting game, Python is there for you with pygame. There are books available for pygame: Beginning Game Development with Python and Pygame: From Novice to Professional (Beginning from Novice to Professional), Game Programming With Python (Game Development Series)
- Scientific computing: There is Python module available for numerical programming (numpy) and also there is another module that can be used for programming in bioinformatics. There are two complete books available for this: Python For Bioinformatics (Jones and Bartlett Series in Biomedical Informatics) and Bioinformatics Programming in Python: A Practical Course for Beginners
Last but not the least, Python is one of the three official programming languages of Google!
Please add if I missed anything important.