python - Save session in IPython like in MATLAB?

Question

It would be useful to save the session variables which could be loaded easily into memory at a later stage.

Answer 1

In [23]: %logstart /tmp/session.log
Activating auto-logging. Current session state plus future input saved.
Filename       : /tmp/session.log
Mode           : backup
Output logging : False
Raw input log  : False
Timestamping   : False
State          : active

In [24]: x = 1

In [25]: %logstop

In [26]: quit()
Do you really want to exit ([y]/n)? y

Then we can restore the session with:

% ipython -log /tmp/session.log 
Activating auto-logging. Current session state plus future input saved.
Filename       : ipython_log.py
...

In [1]: x
Out[1]: 1

For more on "Session logging and restoring" see the docs.

Note that this merely stores the commands run by IPython. It does not save the state of the IPython session. Restoring the session requires re-execution of the commands.

---

If you set the PYTHONSTARTUP environment variable to point at a file called, say, startup.py:

PYTHONSTARTUP=/path/to/startup.py

then put the following in /path/to/startup.py:

try:
    # https://stackoverflow.com/a/5377051/190597 (Tom Dunham)
    __IPYTHON__
except NameError:
    pass
else:
    # https://stackoverflow.com/a/15898875/190597 (user2261139)
    from IPython import get_ipython
    ipython = get_ipython()
    ipython.magic("%logstart /tmp/session.log")

then IPython will call %logstart automatically whenever you start an interactive session.