reload (update) a module file in the interpreter

Question

Let's say I have this python script script.py and I load it in the interpreter by typing

import script

and then I execute my function by typing:

script.testFunction(testArgument)

OK so far so good, but when I change script.py, if I try to import again the script doesn't update. I have to exit from the interpreter, restart the interpreter, and then import the new version of the script for it to work.

What should I do instead?

Argumentative

Question: hhhhmmm, how would I reload this module named 'script'? Answer: reload(script). +1 for Python! – Haddad

BTW I love somebody edited my original question !!! LoL!! – Argumentative

Answer 1

You can issue a reload script, but that will not update your existing objects and will not go deep inside other modules.

Fortunately this is solved by IPython - a better python shell which supports auto-reloading.

To use autoreloading in IPython, you'll have to type import ipy_autoreload first, or put it permanently in your ~/.ipython/ipy_user_conf.py.

Then run:

%autoreload 1
%aimport script

%autoreload 1 means that every module loaded with %aimport will be reloaded before executing code from the prompt. This will not update any existing objects, however.

See http://ipython.org/ipython-doc/dev/config/extensions/autoreload.html for more fun things you can do.

Stagecoach

You can also do %load_ext autoreload ipython.org/ipython-doc/dev/config/extensions/autoreload.html – Hsiuhsu

Answer 2

http://docs.python.org/library/functions.html#reload

reload(module)

Reload a previously imported module. The argument must be a module object, so it must have been successfully imported before. This is useful if you have edited the module source file using an external editor and want to try out the new version without leaving the Python interpreter. The return value is the module object (the same as the module argument).

Neural

Aye, it does need a sarcasm font. My thanks were sincere. – Neural

Answer 3

An alternative solution that has helped me greatly is to maintain a copy of sys.modules keys and pop the new modules after the import to force re-imports of deep imports:

>>> oldmods = set(sys.modules.keys())
>>> import script
>>> # Do stuff
>>> for mod in set(sys.modules.keys()).difference(oldmods): sys.modules.pop(mod)
>>> import script

Attribution