Command history in a Python 3 virtualenv

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Due to a long standing bug, no history file will be kept of the commands you enter in an interactive shell when using a Python 3 virtualenv.

I found out a simple workaround. Simply put the following in your ~/.pythonrc :

import atexit, os, readline, sys
if sys.version_info >= (3, 0) and hasattr(sys, 'real_prefix'): # in a VirtualEnv
    PYTHON_HISTORY_FILE = os.path.join(os.environ['HOME'], '.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)

.pythonrc files are loaded at startup by defining a PYTHONSTARTUP environment variable pointing to them. I prefer to load mine only when launching a REPL, but never when passing parameters to the python command (like script names), so I use the following function definion in my .bashrc :

python () {
    if [ "$#" -eq 0 ]; then
        PYTHONSTARTUP=~/.pythonrc $(type -P python)
    else
        $(type -P python) "$@"
    fi
}
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