How to save a Python interactive session?

Question

I find myself frequently using Python's interpreter to work with databases, files, etc -- basically a lot of manual formatting of semi-structured data. I don't properly save and clean up the useful bits as often as I would like. Is there a way to save my input into the shell (db connections, variable assignments, little for loops and bits of logic) -- some history of the interactive session? If I use something like script I get too much stdout noise. I don't really need to pickle all the objects -- though if there is a solution that does that, it would be OK. Ideally I would just be left with a script that ran as the one I created interactively, and I could just delete the bits I didn't need. Is there a package that does this, or a DIY approach?

UPDATE: I am really amazed at the quality and usefulness of these packages. For those with a similar itch:

• IPython -- should have been using this for ages, kind of what I had in mind
• reinteract -- very impressive, I want to learn more about visualization and this seems like it will shine there. Sort of a gtk/gnome desktop app that renders graphs inline. Imagine a hybrid shell + graphing calculator + mini eclipse. Source distribution here: http://www.reinteract.org/trac/wiki/GettingIt . Built fine on Ubuntu, integrates into gnome desktop, Windows and Mac installers too.
• bpython -- extremely cool, lots of nice features, autocomplete(!), rewind, one keystroke save to file, indentation, well done. Python source distribution, pulled a couple of dependencies from sourceforge.

I am converted, these really fill a need between interpreter and editor.

Answer 1

There is a way to do it. Store the file in ~/.pystartup

# Add auto-completion and a stored history file of commands to your Python
# interactive interpreter. Requires Python 2.0+, readline. Autocomplete is
# bound to the Esc key by default (you can change it - see readline docs).
#
# Store the file in ~/.pystartup, and set an environment variable to point
# to it:  "export PYTHONSTARTUP=/home/user/.pystartup" in bash.
#
# Note that PYTHONSTARTUP does *not* expand "~", so you have to put in the
# full path to your home directory.

import atexit
import os
import readline
import rlcompleter

historyPath = os.path.expanduser("~/.pyhistory")

def save_history(historyPath=historyPath):
    import readline
    readline.write_history_file(historyPath)

if os.path.exists(historyPath):
    readline.read_history_file(historyPath)

atexit.register(save_history)
del os, atexit, readline, rlcompleter, save_history, historyPath

You can also add this to get autocomplete for free:

readline.parse_and_bind('tab: complete')

Please note that this will only work on *nix systems. As readline is only available in Unix platform.

Answer 2

IPython is extremely useful if you like using interactive sessions. For example for your usecase there is the save command, you just input save my_useful_session 10-20 23 to save input lines 10 to 20 and 23 to my_useful_session.py. (to help with this, every line is prefixed by its number)

Look at the videos on the documentation page to get a quick overview of the features.

Answer 3

Also, reinteract gives you a notebook-like interface to a Python session.

Answer 4

In addition to IPython, a similar utility bpython has a "save the code you've entered to a file" feature