automatically save ipython sessions

save_user_variables.md

I often like to start my ipython session from where I last left off - similar to saving a firefox browsing session. IPython already automatically saves your input history so that you can look up commands in your history, but it doesn't save your variables. Here are the steps to save the state of your variables on exit and have them loaded on startup:

1. Add the save_user_variables.py script below to your ipython folder (by default $HOME/.ipython). This script takes care of saving user variables on exit.

2. Add this line to your profile's ipython startup script (e.g., $HOME/.ipython/profile_default/startup/startup.py):
   get_ipython().ex("import save_user_variables;del save_user_variables")

3. In your ipython profile config file (by default $HOME/.ipython/profile_default/ipython_config.py) find the following line:
   # c.StoreMagics.autorestore = False
   Uncomment it and set it to true. This automatically reloads stored variables on startup. Alternatively you can use reload the last session manually using %store -r.

FYI this was tested using IPython version 2.1.0 in linux mint.

save_user_variables.py

def get_response(quest,default=None,opts=('y','n'),please=None,fmt=None):
    try:
        raw_input = input
    except NameError:
        pass
    quest += " ("
    quest += "/".join(['['+o+']' if o==default else o for o in opts])
    quest += "): "

    if default is not None: opts = list(opts)+['']
    if please is None: please = quest
    if fmt is None: fmt = lambda x: x

    rin = input(quest)
    while fmt(rin) not in opts: rin = input(please)

    return default if default is not None and rin == '' else fmt(rin)

def get_user_vars():
    """
    Get variables in user namespace (ripped directly from ipython namespace
    magic code)
    """
    import IPython
    ip = IPython.get_ipython()    
    user_ns = ip.user_ns
    user_ns_hidden = ip.user_ns_hidden
    nonmatching = object()
    var_hist = [ i for i in user_ns
                 if not i.startswith('_') \
                 and (user_ns[i] is not user_ns_hidden.get(i, nonmatching)) ]
    return var_hist

def shutdown_logger():
    """
    Prompts for saving the current session during shutdown
    """
    import IPython, pickle
    var_hist = get_user_vars()
    ip = IPython.get_ipython()
    db = ip.db

    # collect any variables that need to be deleted from db
    keys = map(lambda x: x.split('/')[1], db.keys('autorestore/*'))
    todel = set(keys).difference(ip.user_ns)
    changed = [db[k] != ip.user_ns[k.split('/')[1]]
               for k in db.keys('autorestore/*') if k.split('/')[1] in ip.user_ns]

    try:
        if len(var_hist) == 0 and len(todel) == 0 and not any(changed): return
        if get_response("Save session?", 'n', fmt=str.lower) == 'n': return
    except KeyboardInterrupt:
        return

    # Save interactive variables (ignore unsaveable ones)
    for name in var_hist:
        obj = ip.user_ns[name]
        try:
            db[ 'autorestore/' + name ] = obj
        except pickle.PicklingError:
            print("Could not store variable '%s'. Skipping..." % name)
            del db[ 'autorestore/' + name ]

    # Remove any previously stored variables that were deleted in this session
    for k in todel:
        del db['autorestore/'+k]

import atexit
atexit.register(shutdown_logger)
del atexit

@tgarc, saw your answer on Stackoverflow on how to save variable on exit, using the above script.

does this still work with Ipython 6.0 or recent ones? I tried on Windows 10, ipython 6, and it didnt work..

Sorry @alphaCTzo7G your message got buried in my inbox. Try the new edits I made. Works as before using IPython 6 on my windows machine.