This had been bugging me all day in the back of my head... turns out shuffle is enabled by default. Both in sklearn and in tf.keras (also original keras).

On a separate note, I think there may be a source file missing in your notebook. I kept getting an error when trying to load "GSE87571_series_matrix.csv". Might just be me.

[sklearn ref](https://scikit-learn.org/stable/modules/generated/sklearn.mo...)

[tf.keras](https://www.tensorflow.org/api_docs/python/tf/keras/Model#fi...)