pandas.DataFrame.loc

DataFrame.loc

Purely label-location based indexer for selection by label.

.loc[] is primarily label based, but may also be used with a boolean array.

Allowed inputs are:

• A single label, e.g. 5 or 'a', (note that 5 is interpreted as a label of the index, and never as an integer position along the index).
• A list or array of labels, e.g. ['a', 'b', 'c'].
• A slice object with labels, e.g. 'a':'f' (note that contrary to usual python slices, both the start and the stop are included!).
• A boolean array.
• A callable function with one argument (the calling Series, DataFrame or Panel) and that returns valid output for indexing (one of the above)

.loc will raise a KeyError when the items are not found.

See more at Selection by Label