number of terms in the
          contraction.
        * 'greedy' An algorithm that chooses the best pair contraction
          at each step. Effectively, this algorithm searches the largest inner,
          Hadamard, and then outer products at each step. Scales cubically with
          the number of terms in the contraction. Equivalent to the 'optimal'
          path for most contractions.

        Default is 'greedy'.

    Returns
    -------
    path : list of tuples
        A list representation of the einsum path.
    string_repr : str
        A printable representation of the einsum path.

    Notes
    -----
    The resulting path indicates which terms of the input contraction should be
    contracted first, the result of this contraction is then appended to the
    end of the contraction list. This list can then be iterated over until all
    intermediate contractions are complete.

    See Also
    --------
    einsum, linalg.multi_dot

    Examples
    --------

    We can begin with a chain dot example. In this case, it is optimal to
    contract the ``b`` and ``c`` tensors first as represented by the first
    element of the path ``(1, 2)``. The resulting tensor is added to the end
    of the contraction and the remaining contraction ``(0, 1)`` is then
    completed.

    >>> np.random.seed(123)
    >>> a = np.random.rand(2, 2)
    >>> b = np.random.rand(2, 5)
    >>> c = np.random.rand(5, 2)
    >>> path_info = np.einsum_path('ij,jk,kl->il', a, b, c, optimize='greedy')
    >>> print(path_info[0])
    ['einsum_path', (1, 2), (0, 1)]
    >>> print(path_info[1])
      Complete contraction:  ij,jk,kl->il # may vary
             Naive scaling:  4
         Optimized scaling:  3
          Naive FLOP count:  1.600e+02
      Optimized FLOP count:  5.600e+01
       Theoretical speedup:  2.857
      Largest intermediate:  4.000e+00 elements
    -------------------------------------------------------------------------
    scaling                  current                                remaining
    -------------------------------------------------------------------------
       3                   kl,jk->jl                                ij,jl->il
       3                   jl,ij->il                                   il->il


    A more complex index transformation example.

    >>> I = np.random.rand(10, 10, 10, 10)
    >>> C = np.random.rand(10, 10)
    >>> path_info = np.einsum_path('ea,fb,abcd,gc,hd->efgh', C, C, I, C, C,
    ...                            optimize='greedy')

    >>> print(path_info[0])
    ['einsum_path', (0, 2), (0, 3), (0, 2), (0, 1)]
    >>> print(path_info[1]) 
      Complete contraction:  ea,fb,abcd,gc,hd->efgh # may vary
             Naive scaling:  8
         Optimized scaling:  5
          Naive FLOP count:  8.000e+08
      Optimized FLOP count:  8.000e+05
       Theoretical speedup:  1000.000
      Largest intermediate:  1.000e+04 elements
    --------------------------------------------------------------------------
    scaling                  current                                remaining
    --------------------------------------------------------------------------
       5               abcd,ea->bcde                      fb,gc,hd,bcde->efgh
       5               bcde,fb->cdef                         gc,hd,cdef->efgh
       5               cdef,gc->defg                            hd,defg->efgh
       5               defg,hd->efgh                               efgh->efgh
    Tr