Python: reload component Y imported with 'from X import Y'?

Question

In Python, once I have imported a module X in an interpreter session using import X, and the module changes on the outside, I can reload the module with reload(X). The changes then become available in my interpreter session.

I am wondering if this also possible when I import a component Y from module X using from X import Y.

The statement reload Y does not work, since Y is not a module itself, but only a component (in this case a class) inside of a module.

Is it possible at all to reload individual components of a module without leaving the interpreter session (or importing the entire module)?

EDIT:

For clarification, the question is about importing a class or function Y from a module X and reloading on a change, not a module Y from a package X.

Answer 1

Answer

From my tests, the marked answer, which suggests a simple reload(X), does not work.

From what I can tell the correct answer is:

from importlib import reload # python 2.7 does not require this import X reload( X ) from X import Y 

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Test

My test was the following (Python 2.6.5 + bpython 0.9.5.2)

X.py:

def Y():     print "Test 1" 

bpython:

>>> from X import Y >>> print Y() Test 1 >>> # Edit X.py to say "Test 2" >>> print Y() Test 1 >>> reload( X )  # doesn't work because X not imported yet Traceback (most recent call last):   File "<input>", line 1, in <module> NameError: name 'X' is not defined >>> import X >>> print Y() Test 1 >>> print X.Y() Test 1 >>> reload( X ) # No effect on previous "from" statements >>> print Y() Test 1 >>> print X.Y() # first one that indicates refresh Test 2 >>> from X import Y >>> print Y() Test 2  >>> # Finally get what we were after