Method from_tuples

pandas/core/indexes/multi.py:515–591

Convert list of tuples to MultiIndex. Parameters ---------- tuples : list / sequence of tuple-likes Each tuple is the index of one row/column. sortorder : int or None Level of sortedness (must be lexicographically sorted by that

(
        cls,
        tuples: Iterable[tuple[Hashable, ...]],
        sortorder: int | None = None,
        names: Sequence[Hashable] | Hashable | None = None,
    )

    @classmethod
    @names_compat
    def from_tuples(
        cls,
        tuples: Iterable[tuple[Hashable, ...]],
        sortorder: int | None = None,
        names: Sequence[Hashable] | Hashable | None = None,
    ) -> MultiIndex:
        """
        Convert list of tuples to MultiIndex.

        Parameters
        ----------
        tuples : list / sequence of tuple-likes
            Each tuple is the index of one row/column.
        sortorder : int or None
            Level of sortedness (must be lexicographically sorted by that
            level).
        names : list / sequence of str, optional
            Names for the levels in the index.

        Returns
        -------
        MultiIndex

        See Also
        --------
        MultiIndex.from_arrays : Convert list of arrays to MultiIndex.
        MultiIndex.from_product : Make a MultiIndex from cartesian product
                                  of iterables.
        MultiIndex.from_frame : Make a MultiIndex from a DataFrame.

        Examples
        --------
        >>> tuples = [(1, "red"), (1, "blue"), (2, "red"), (2, "blue")]
        >>> pd.MultiIndex.from_tuples(tuples, names=("number", "color"))
        MultiIndex([(1,  'red'),
                    (1, 'blue'),
                    (2,  'red'),
                    (2, 'blue')],
                   names=['number', 'color'])
        """
        if not is_list_like(tuples):
            raise TypeError("Input must be a list / sequence of tuple-likes.")
        if is_iterator(tuples):
            tuples = list(tuples)
        tuples = cast(Collection[tuple[Hashable, ...]], tuples)

        # handling the empty tuple cases
        if len(tuples) and all(isinstance(e, tuple) and not e for e in tuples):
            codes = [np.zeros(len(tuples))]
            levels = [Index(com.asarray_tuplesafe(tuples, dtype=np.dtype("object")))]
            return cls(
                levels=levels,
                codes=codes,
                sortorder=sortorder,
                names=names,
                verify_integrity=False,
            )