How can I capture return value with Python timeit module?

Question

Im running several machine learning algorithms with sklearn in a for loop and want to see how long each of them takes. The problem is I also need to return a value and DONT want to have to run it more than once because each algorithm takes so long. Is there a way to capture the return value 'clf' using python's timeit module or a similar one with a function like this...

def RandomForest(train_input, train_output):
    clf = ensemble.RandomForestClassifier(n_estimators=10)
    clf.fit(train_input, train_output)
    return clf

when I call the function like this

t = Timer(lambda : RandomForest(trainX,trainy))
print t.timeit(number=1)

P.S. I also dont want to set a global 'clf' because I might want to do multithreading or multiprocessing later.

Answer 1

For Python 3.5 you can override the value of timeit.template

timeit.template = """
def inner(_it, _timer{init}):
    {setup}
    _t0 = _timer()
    for _i in _it:
        retval = {stmt}
    _t1 = _timer()
    return _t1 - _t0, retval
"""

unutbu's answer works for python 3.4 but not 3.5 as the _template_func function appears to have been removed in 3.5