Tips and Tricks for the Python Interpreter
I have seen a lot of people switch over to using ipython, bpython, etc to get auto-complete support without realizing that the standard interpreter does have this functionality.
To enable auto-complete support in the python interpreter you need to create a python startup file that enables readline support. A python startup file is just a bunch of python code that gets executed at startup of the interpreter. To do this you just setup PYTHONSTARTUP in your ~/.bashrc and then create a ~/.pythonrc.py file:
#.bashrc PYTHONSTARTUP=~/.pythonrc.py export PYTHONSTARTUP #.pythonrc.py try: import readline except ImportError: print("Module readline not available.") else: import rlcompleter readline.parse_and_bind("tab: complete")
Now when you are in python you have tab completion on importing, calling methods on a module, etc.
import o object( oct( open( or ord( os
I always end up using the pretty print module for viewing long lists and strings in the interpreter so I prefer to just use it by default:
# Enable Pretty Printing for stdout import pprint def my_displayhook(value): if value is not None: try: import __builtin__ __builtin__._ = value except ImportError: __builtins__._ = value pprint.pprint(value) sys.displayhook = my_displayhook
It is also very useful to be able to load up your favorite editor to edit lines of code from the interpreter, you can do this by adding the following into your ~/.pythonrc.py:
import os import sys from code import InteractiveConsole from tempfile import mkstemp EDITOR = os.environ.get('EDITOR', 'vi') EDIT_CMD = '\e' class EditableBufferInteractiveConsole(InteractiveConsole): def __init__(self, *args, **kwargs): self.last_buffer =  # This holds the last executed statement InteractiveConsole.__init__(self, *args, **kwargs) def runsource(self, source, *args): self.last_buffer = [ source.encode('latin-1') ] return InteractiveConsole.runsource(self, source, *args) def raw_input(self, *args): line = InteractiveConsole.raw_input(self, *args) if line == EDIT_CMD: fd, tmpfl = mkstemp('.py') os.write(fd, b'\n'.join(self.last_buffer)) os.close(fd) os.system('%s %s' % (EDITOR, tmpfl)) line = open(tmpfl).read() os.unlink(tmpfl) tmpfl = '' lines = line.split( '\n' ) for i in range(len(lines) - 1): self.push( lines[i] ) line = lines[-1] return line c = EditableBufferInteractiveConsole(locals=locals()) c.interact(banner='') # Exit the Python shell on exiting the InteractiveConsole sys.exit()
For Django developers when you load up the ./manage.py shell it is nice to have access to all your models and settings for testing:
# If we're working with a Django project, set up the environment if 'DJANGO_SETTINGS_MODULE' in os.environ: from django.db.models.loading import get_models from django.test.client import Client from django.test.utils import setup_test_environment, teardown_test_environment from django.conf import settings as S class DjangoModels(object): """Loop through all the models in INSTALLED_APPS and import them.""" def __init__(self): for m in get_models(): setattr(self, m.__name__, m) A = DjangoModels() C = Client()
After these tweaks the python interpreter is a lot more powerful and you really lose the need for the more interactive shells like ipython and bpython. All of these settings work in both python2 and python3.
If you want to see my complete ~/.pythonrc.py you can get it on github