Expert Python Programming - Third Edition

Custom Python shells – ipython, bpython, ptpython, and so on

Python programmers spend a lot of time in interactive interpreter sessions. It is very good for testing small code snippets, accessing documentation, or even debugging code at runtime. The default interactive Python session is very simple, and does not provide many features, such as tab completion or code introspection helpers. Fortunately, the default Python shell can be easily extended and customized.

If you use an interactive shell very often, you can easily modify the behavior of it prompt. Python at startup reads the PYTHONSTARTUP environment variable, looking for the path of the custom initializations script. Some operating system distributions where Python is a common