# [2019.04.09] loc vs iloc

Interestingly, these two methods in `pandas.DataFrame` are base on
two different low-level libraries and `iloc` _excludes_ the right
boundary of the slice, although `loc` includes:( I took a `pandas`
micro-course from Kaggle today and found several things I didn't know
before, e.g. methods `value_counts` (more effective than `groupby`
followed by `count`) and `idxmax` (kind of `argmax`, so missing in
SQL:)).