For all operands that are merely of type str or int, substitute
    LocalSpace objects with corresponding labels:
    For a string, just itself, for an int, a string version of that int.

def convert_to_spaces(cls, ops, kwargs):
    """For all operands that are merely of type str or int, substitute
    LocalSpace objects with corresponding labels:
    For a string, just itself, for an int, a string version of that int.
    """
    from qnet.algebra.core.hilbert_space_algebra import (
        HilbertSpace, LocalSpace)
    cops = [o if isinstance(o, HilbertSpace) else LocalSpace(o) for o in ops]
    return cops, kwargs