Tab-Complete and a Persistent History in Python

November 17, 2006 at 9:15 pm | Posted in python | 4 Comments

Earlier today, in #django on freenode, the topic of tab-complete in the python shell happened to come up – at first, I thought it wasn’t possible in standard python, and only in other python interpreters.

Thankfully, a link was posted with info on the readline and rlcomplete modules – at first, I couldn’t get their example working to load on startup, so upon further investigation, not only did I get that quirk worked out, but I stumbled across another module that lets you hook on start/exit to save/load a history file, much like bash.

Anyway, without any further ado, here’s the short and sweet version to get this setup:

import atexit
import os

historyPath = os.path.expanduser("~/.pyhistory")

try:
    import readline
except ImportError:
    print "Module readline not available."
else:
    import rlcompleter
    readline.parse_and_bind("tab: complete")
    if os.path.exists(historyPath):
        readline.read_history_file(historyPath)

def save_history(historyPath=historyPath):
    try:
        import readline
    except ImportError:
        print "Module readline not available."
    else:
        readline.write_history_file(historyPath)

atexit.register(save_history)

Drop that in a file such as .pythonrc in your home directory, then point python to that by adding the path to the PYTHONSTARTUP environment variable in .bashrc or .bash_profile

Advertisements