def test_pipeline_init_tuple():
    # Pipeline accepts steps as tuple
    X = np.array([[1, 2]])
    pipe = Pipeline((('transf', Transf()), ('clf', FitParamT())))
    pipe.fit(X, y=None)
    pipe.score(X)

    pipe.set_params(transf=None)
    pipe.fit(X, y=None)
    pipe.score(X)
def test_set_pipeline_steps():
    transf1 = Transf()
    transf2 = Transf()
    pipeline = Pipeline([('mock', transf1)])
    assert pipeline.named_steps['mock'] is transf1

    # Directly setting attr
    pipeline.steps = [('mock2', transf2)]
    assert 'mock' not in pipeline.named_steps
    assert pipeline.named_steps['mock2'] is transf2
    assert_equal([('mock2', transf2)], pipeline.steps)

    # Using set_params
    pipeline.set_params(steps=[('mock', transf1)])
    assert_equal([('mock', transf1)], pipeline.steps)

    # Using set_params to replace single step
    pipeline.set_params(mock=transf2)
    assert_equal([('mock', transf2)], pipeline.steps)

    # With invalid data
    pipeline.set_params(steps=[('junk', ())])
    assert_raises(TypeError, pipeline.fit, [[1]], [1])
    assert_raises(TypeError, pipeline.fit_transform, [[1]], [1])
def test_set_params_nested_pipeline():
    estimator = Pipeline([('a', Pipeline([('b', DummyRegressor())]))])
    estimator.set_params(a__b__alpha=0.001, a__b=Lasso())
    estimator.set_params(a__steps=[('b', LogisticRegression())], a__b__C=5)
def test_pipeline_init():
    # Test the various init parameters of the pipeline.
    assert_raises(TypeError, Pipeline)
    # Check that we can't instantiate pipelines with objects without fit
    # method
    assert_raises_regex(
        TypeError, 'Last step of Pipeline should implement fit. '
        '.*NoFit.*', Pipeline, [('clf', NoFit())])
    # Smoke test with only an estimator
    clf = NoTrans()
    pipe = Pipeline([('svc', clf)])
    assert_equal(
        pipe.get_params(deep=True),
        dict(svc__a=None, svc__b=None, svc=clf, **pipe.get_params(deep=False)))

    # Check that params are set
    pipe.set_params(svc__a=0.1)
    assert_equal(clf.a, 0.1)
    assert_equal(clf.b, None)
    # Smoke test the repr:
    repr(pipe)

    # Test with two objects
    clf = SVC()
    filter1 = SelectKBest(f_classif)
    pipe = Pipeline([('anova', filter1), ('svc', clf)])

    # Check that we can't instantiate with non-transformers on the way
    # Note that NoTrans implements fit, but not transform
    assert_raises_regex(
        TypeError, 'All intermediate steps should be transformers'
        '.*\\bNoTrans\\b.*', Pipeline, [('t', NoTrans()), ('svc', clf)])

    # Check that params are set
    pipe.set_params(svc__C=0.1)
    assert_equal(clf.C, 0.1)
    # Smoke test the repr:
    repr(pipe)

    # Check that params are not set when naming them wrong
    assert_raises(ValueError, pipe.set_params, anova__C=0.1)

    # Test clone
    pipe2 = assert_no_warnings(clone, pipe)
    assert_false(pipe.named_steps['svc'] is pipe2.named_steps['svc'])

    # Check that apart from estimators, the parameters are the same
    params = pipe.get_params(deep=True)
    params2 = pipe2.get_params(deep=True)

    for x in pipe.get_params(deep=False):
        params.pop(x)

    for x in pipe2.get_params(deep=False):
        params2.pop(x)

    # Remove estimators that where copied
    params.pop('svc')
    params.pop('anova')
    params2.pop('svc')
    params2.pop('anova')
    assert_equal(params, params2)