[python] save a pandas.Series histogram plot to file

In ipython Notebook, first create a pandas Series object, then by calling the instance method .hist(), the browser displays the figure.

I am wondering how to save this figure to a file (I mean not by right click and save as, but the commands needed in the script).

You can use ax.figure.savefig():

import pandas as pd

s = pd.Series([0, 1])
ax = s.plot.hist()
ax.figure.savefig('demo-file.pdf')

This has no practical benefit over ax.get_figure().savefig() as suggested in Philip Cloud's answer, so you can pick the option you find the most aesthetically pleasing. In fact, get_figure() simply returns self.figure:

# Source from snippet linked above
def get_figure(self):
    """Return the `.Figure` instance the artist belongs to."""
    return self.figure