align.py 文件源码

def _reconstruct_object(typ, obj, axes, dtype):
    """Reconstruct an object given its type, raw value, and possibly empty
    (None) axes.

    Parameters
    ----------
    typ : object
        A type
    obj : object
        The value to use in the type constructor
    axes : dict
        The axes to use to construct the resulting pandas object

    Returns
    -------
    ret : typ
        An object of type ``typ`` with the value `obj` and possible axes
        `axes`.
    """
    try:
        typ = typ.type
    except AttributeError:
        pass

    res_t = np.result_type(obj.dtype, dtype)

    if (not isinstance(typ, partial) and
            issubclass(typ, pd.core.generic.PandasObject)):
        return typ(obj, dtype=res_t, **axes)

    # special case for pathological things like ~True/~False
    if hasattr(res_t, 'type') and typ == np.bool_ and res_t != np.bool_:
        ret_value = res_t.type(obj)
    else:
        ret_value = typ(obj).astype(res_t)
        # The condition is to distinguish 0-dim array (returned in case of
        # scalar) and 1 element array
        # e.g. np.array(0) and np.array([0])
        if len(obj.shape) == 1 and len(obj) == 1:
            if not isinstance(ret_value, np.ndarray):
                ret_value = np.array([ret_value]).astype(res_t)

    return ret_value