Give the Python Terminal a Persistent History

Question

Is there a way to tell the interactive Python shell to preserve its history of executed commands between sessions?

While a session is running, after commands have be

Answer 1

Sure you can, with a small startup script. From Interactive Input Editing and History Substitution in the python tutorial:

# 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=~/.pystartup" in bash.

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

From Python 3.4 onwards, the interactive interpreter supports autocompletion and history out of the box:

Tab-completion is now enabled by default in the interactive interpreter on systems that support readline. History is also enabled by default, and is written to (and read from) the file ~/.python-history.

Answer 2

This is also required for Python 3 when using a virtual environment.

I use a slightly different version which keeps a history file per virtual environment:

import sys

if sys.version_info >= (3, 0) and hasattr(sys, 'real_prefix'):  # in a VirtualEnv
    import atexit, os, readline, sys

    PYTHON_HISTORY_FILE = os.path.join(os.environ['VIRTUAL_ENV'], '.python_history')
    if os.path.exists(PYTHON_HISTORY_FILE):
        readline.read_history_file(PYTHON_HISTORY_FILE)
    atexit.register(readline.write_history_file, PYTHON_HISTORY_FILE)

Answer 3

Use IPython.

You should, anyway, because it's awesome: persistent command history is just one of the many many ways it's better than the stock Python shell.