Method get_loc

pandas/core/indexes/base.py:3601–3654

Get integer location, slice or boolean mask for requested label. Parameters ---------- key : label The key to check its location if it is present in the index. Returns ------- int if unique index, slice if monotonic index, else m

(self, key)

    # Indexing Methods

    def get_loc(self, key):
        """
        Get integer location, slice or boolean mask for requested label.

        Parameters
        ----------
        key : label
            The key to check its location if it is present in the index.

        Returns
        -------
        int if unique index, slice if monotonic index, else mask
            Integer location, slice or boolean mask.

        See Also
        --------
        Index.get_slice_bound : Calculate slice bound that corresponds to
            given label.
        Index.get_indexer : Computes indexer and mask for new index given
            the current index.
        Index.get_non_unique : Returns indexer and masks for new index given
            the current index.
        Index.get_indexer_for : Returns an indexer even when non-unique.

        Examples
        --------
        >>> unique_index = pd.Index(list("abc"))
        >>> unique_index.get_loc("b")
        1

        >>> monotonic_index = pd.Index(list("abbc"))
        >>> monotonic_index.get_loc("b")
        slice(1, 3, None)

        >>> non_monotonic_index = pd.Index(list("abcb"))
        >>> non_monotonic_index.get_loc("b")
        array([False,  True, False,  True])
        """
        casted_key = self._maybe_cast_indexer(key)
        try:
            return self._engine.get_loc(casted_key)
        except KeyError as err:
            if isinstance(casted_key, slice) or (
                isinstance(casted_key, abc.Iterable)
                and any(isinstance(x, slice) for x in casted_key)
            ):
                raise InvalidIndexError(key) from err
            raise KeyError(key) from err
        except TypeError:
            # If we have a listlike key, _check_indexing_error will raise
            #  InvalidIndexError. Otherwise we fall through and re-raise
            #  the TypeError.
            self._check_indexing_error(key)
            raise

    @final
    def get_indexer(