Save an IPython notebook programmatically from within itself?

I am taking @Taar’s comment and making it an actual answer since it worked for the original person who asked the question and for myself.

from IPython.display import display, Javascript
display(Javascript('IPython.notebook.save_checkpoint();'))

This will create checkpoints – same thing as CTRL-s.

Note: in Jupyter, CTRL-s triggers an async process and the file save is actually completed only a few seconds later. If you want a blocking save operation in a notebook, use this little function (file_path is the path to the notebook file):

import time
from IPython.display import display, Javascript
import hashlib

def save_notebook(file_path):
    start_md5 = hashlib.md5(open(file_path,'rb').read()).hexdigest()
    display(Javascript('IPython.notebook.save_checkpoint();'))
    current_md5 = start_md5
    
    while start_md5 == current_md5:
        time.sleep(1)
        current_md5 = hashlib.md5(open(file_path,'rb').read()).hexdigest()