How to use the pdpipe.core.Pipeline function in pdpipe

def test_pipeline_stage_to_pipeline_addition():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    pipeline = Pipeline([drop_num1])
    assert len(pipeline) == 1
    pipeline = drop_num2 + pipeline
    assert len(pipeline) == 2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns

def test_two_stage_pipeline_stage():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    pipeline = Pipeline([drop_num1, drop_num2])
    assert len(pipeline) == 2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns
    str(pipeline)

    # test fit_transform
    df = _test_df()
    res_df = pipeline.fit_transform(df, verbose=True)

    # test get_transformer
    trs = lambda pipline: pipeline[:1]  # noqa: E731
    pipeline = Pipeline([drop_num1, drop_num2], transformer_getter=trs)
    transformer = pipeline.get_transformer()

def test_pipeline_to_pipeline_addition():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    pipeline1 = Pipeline([drop_num1])
    pipeline2 = Pipeline([drop_num2])
    pipeline = pipeline1 + pipeline2
    assert len(pipeline) == 2
    assert pipeline[0] == drop_num1
    assert pipeline[1] == drop_num2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns

def test_pipeline_to_pipeline_stage_addition():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    pipeline = Pipeline([drop_num1])
    assert len(pipeline) == 1
    pipeline = pipeline + drop_num2
    assert len(pipeline) == 2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns

def test_pipeline_slice():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    drop_char = SilentDropStage('char')
    pipeline = Pipeline([drop_num1, drop_num2, drop_char])
    assert len(pipeline) == 3
    pipeline = pipeline[0:2]
    assert len(pipeline) == 2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns

pipeline = Pipeline([drop_num1, drop_num2])
    assert len(pipeline) == 2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns
    str(pipeline)

    # test fit_transform
    df = _test_df()
    res_df = pipeline.fit_transform(df, verbose=True)

    # test get_transformer
    trs = lambda pipline: pipeline[:1]  # noqa: E731
    pipeline = Pipeline([drop_num1, drop_num2], transformer_getter=trs)
    transformer = pipeline.get_transformer()
    res_df = transformer(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' in res_df.columns
    assert 'char' in res_df.columns

def test_pipeline_index():
    """Testing something."""
    df = _test_df()
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    drop_char = SilentDropStage('char')
    pipeline = Pipeline([drop_num1, drop_num2, drop_char])
    assert len(pipeline) == 3
    assert pipeline[0] == drop_num1
    assert 'num1' not in pipeline[0](df).columns
    assert pipeline[1] == drop_num2
    assert 'num2' not in pipeline[1](df).columns
    assert pipeline[2] == drop_char
    assert 'char' not in pipeline[2](df).columns

def test_pipeline_to_pipeline_addition():
    """Testing something."""
    drop_num1 = SilentDropStage('num1')
    drop_num2 = SilentDropStage('num2')
    pipeline1 = Pipeline([drop_num1])
    pipeline2 = Pipeline([drop_num2])
    pipeline = pipeline1 + pipeline2
    assert len(pipeline) == 2
    assert pipeline[0] == drop_num1
    assert pipeline[1] == drop_num2
    df = _test_df()
    res_df = pipeline.apply(df, verbose=True)
    assert 'num1' not in res_df.columns
    assert 'num2' not in res_df.columns
    assert 'char' in res_df.columns