CODEWITHSUNDEEP
pythonimportmodulepycharmpybrain
Eric Gorlin
Eric Gorlin

Reputation: 319

Python Module Update

I have a main file that imports a class from another file as such: 

from pybrain.rl.environments.HoldemTask import HoldemTask.

When I change HoldemTask.py, the changes are not reflected in the main file. The only workaround I have found is to run Pybrain's

python setup.py install

Can I reload the module or something? Reload() doesn't seem to work.

Upvotes: 0

Views: 325

Answers (1)

Walter Mundt
Walter Mundt

Reputation: 25271

First off: python setup.py install generally makes a copy of the code it is installing, so if you're finding that you need to run that before changes take effect, chances are that for development you should be adjusting your PYTHONPATH or sys.path so that your relevant imports come directly from the source tree rather than from the Python site-packages library. You can quickly check which file your code is importing by putting this on the top of the main file when you run it:

from pybrain.rl.environments import HoldemTask # module object, not class
print(HoldemTask.__file__)

Secondly, in general it is far better to restart a Python process when making code changes to ensure that they come into effect. If you really need to get changes to show up without a restart, read on.

Reloading a module in Python only affects future imports. For a reload to work in-process, you have to replace the imported class object after the reload. For example, in the context of the "main file" performing the import you listed (inside a class method or function is fine):

# we need a module object to reload(), not the class inside it
from import pybrain.rl.environments import HoldemTask as HoldemTask_module
reload(HoldemTask_module)
# we then need to replace the old class object with the reloaded one
# in the main file's module-wide (aka "global") namespace
global HoldemTask
HoldemTask = HoldemTask_module.HoldemTask

One final caveat here is that any existing HoldemTask objects will continue to use the old code, because they embed in themselves a reference to the pre-reload class object. The only way for an in-process reload to be complete is if the code is specifically written to throw away every instance of anything it made based on the original module.

Upvotes: 1

Related Questions