from sklearn.datasets import load_iris
from sklearn.base import TransformerMixin
iris = load_iris() #loading dataset
class MultiplyTransformer(TransformerMixin):
    def transform(self, X, y=None):
        return X * 2
    def fit(self, X, y=None):
        return self
multiply_transformer = MultiplyTransformer()
iris_multiplied = multiply_transformer.transform(iris.data)
# printing only first 5 rows
for i in range(5):
    print(iris_multiplied[i])