blender python function to orient an object based on a face normal

facetheworld.py

def faceTheWorld(obj, strMode="EDIT"):
    # Thanks to JohnKaz and Kritskiy on BPY Discord for this function, looks simple, but not easy to figure out!
    mw = obj.matrix_world.copy()
    bm = bmesh.new()
    if strMode == 'OBJECT':
        bm.from_mesh(obj.data)
    else:
        bm = bmesh.from_edit_mesh(obj.data)
    face = next(iter(face for face in bm.faces if face.select), None)

    if not face:
        bm.faces.ensure_lookup_table()
        face = bm.faces[0]

    n = face.normal
    t = face.calc_tangent_edge_pair().normalized()
    c = face.calc_center_median()

    obj.matrix_world = mathutils.Matrix(
        (t.cross(n).normalized(), t, n)).to_4x4() @ mathutils.Matrix.Translation(-c)
    #use this to return it back to original location with
    # obj.matrix_world = the value returned from below
    return mw