CODEWITHSUNDEEP
python
alex
alex

Reputation: 169

reloading module, need to re-compile sub modules?

sorry, im sure this is asked a bunch, but i couldnt find it.

in myModule.py:

from myModule.subModule import myClass

i am working on myClass, and want to stay in my ipython session and test it. reload(myModule) doesnt re-compile myClass.

how can i do this?

Upvotes: 4

Views: 1464

Answers (1)

Alex Martelli
Alex Martelli

Reputation: 882191

You need to repeat your imports after reloading the "leafmost" submodule. E.g., given:

$ mkdir myModule
$ touch myModule/__init__.py
$ cat >myModule/subModule.py
class MyClass(object): kind='first'

and then

>>> from myModule.subModule import MyClass
>>> MyClass.kind
'first'

and in another terminal

$ cat >myModule/subModule.py
class MyClass(object): kind='second'

then...:

>>> import sys
>>> reload(sys.modules['myModule.subModule'])
<module 'myModule.subModule' from 'myModule/subModule.py'>
>>> from myModule.subModule import MyClass
>>> MyClass.kind
'second'

You need to go via sys.modules as you don't otherwise have a reference to the submodule, and then you need to repeat the from.

Life is much simpler if you accept the wise advice of always importing a module, never stuff from INSIDE the module, of course - e.g., the Python session would be (with a change to the submodule before the reload):

>>> from myModule import subModule as sm
>>> sm.MyClass.kind
'first'
>>> reload(sm)
<module 'myModule.subModule' from 'myModule/subModule.py'>
>>> sm.MyClass.kind
'second'

If you get into the habit of using qualified names such as sm.MyClass instead of only the barename MyClass, your life will be simpler in many respects (easier reloading is just one of them;-).

Upvotes: 2

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