How to use the vpython.vec function in vpython

stl_text = stl_file.readlines()

    # Initial Conditions
    triangles = []
    vertices = []
    normal = None

    # For every line in the file
    for line in stl_text:
        file_line = line.split()
        # If blank line (skip)
        if not file_line:
            pass
        # If a face
        elif file_line[0] == b'facet':
            normal = vec(
                float(file_line[2]),
                float(file_line[3]),
                float(file_line[4])
            )
        # If a vertex
        elif file_line[0] == b'vertex':
            vertices.append(
                vertex(
                    pos=vec(
                        float(file_line[1]),
                        float(file_line[2]),
                        float(file_line[3])
                    ),
                    normal=normal,
                    color=color.white
                )

for p in network.Ps:
        r = network[Psize][p]/2
        xyz = network['pore.coords'][p]
        c = Pcolor[p]
        sphere(pos=vec(*xyz), radius=r, color=c,
               shininess=.5)

    for t in network.Ts:
        head = network['throat.endpoints.head'][t]
        tail = network['throat.endpoints.tail'][t]
        v = tail - head
        r = network[Tsize][t]
        L = sp.sqrt(sp.sum((head-tail)**2))
        c = Tcolor[t]
        cylinder(pos=vec(*head), axis=vec(*v), opacity=1, size=vec(L, r, r),
                 color=c)

    return scene

if Pcolor is None:
        Pcolor = [vec(230/255, 57/255, 0/255)]*network.Np
    else:
        a = cmap(network[Pcolor]/network[Pcolor].max())
        Pcolor = [vec(row[0], row[1], row[2]) for row in a]

    if Tcolor is None:
        Tcolor = [vec(51/255, 153/255, 255/255)]*network.Nt
    else:
        a = cmap(network[Tcolor]/network[Tcolor].max())
        Tcolor = [vec(row[0], row[1], row[2]) for row in a]

    # Set default values for canvas properties
    if 'background' not in kwargs.keys():
        kwargs['background'] = vec(1.0, 1.0, 1.0)
    if 'height' not in kwargs.keys():
        kwargs['height'] = 500
    if 'width' not in kwargs.keys():
        kwargs['width'] = 800
    # Parse any given values for canvas properties
    for item in kwargs.keys():
        try:
            kwargs[item] = vec(*kwargs[item])
        except TypeError:
            pass
    scene = canvas(title=network.name, **kwargs)

    for p in network.Ps:
        r = network[Psize][p]/2
        xyz = network['pore.coords'][p]
        c = Pcolor[p]

if t not in rings:
                    rings[t] = []
                if t in tr:
                    if tr[t] not in rings[t]:
                        rings[t].append(tr[t])
                    tr3d[i].append(rings[t].index(tr[t]))
                else:
                    rings[t].append(("unk", -1))
                    tr3d[i].append(len(rings[t]) - 1)

        for t in rings:
            r = rings[t]
            tmp_len = len(r)
            for i in range(tmp_len):
                if r[i][1] == -1:
                    col = vpython.vec(0.75, 0.75, 0.75)
                elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)

elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)
            for ip in trlst:
                vpython.cylinder(pos=start, axis=ip.pos - start, color=col, radius=0.2)  # noqa: E501
                start = ip.pos

        vpython.rate(50)

        # Keys handling
        # TODO: there is currently no way of closing vpython correctly
        # https://github.com/BruceSherwood/vpython-jupyter/issues/36
        # def keyboard_press(ev):
        #     k = ev.key
        #     if k == "esc" or k == "q":
        #         pass  # TODO: close
        #
        # vpython.scene.bind('keydown', keyboard_press)

else:
                    rings[t].append(("unk", -1))
                    tr3d[i].append(len(rings[t]) - 1)

        for t in rings:
            r = rings[t]
            tmp_len = len(r)
            for i in range(tmp_len):
                if r[i][1] == -1:
                    col = vpython.vec(0.75, 0.75, 0.75)
                elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)
            for ip in trlst:
                vpython.cylinder(pos=start, axis=ip.pos - start, color=col, radius=0.2)  # noqa: E501
                start = ip.pos

        vpython.rate(50)

if t not in rings:
                    rings[t] = []
                if t in tr:
                    if tr[t] not in rings[t]:
                        rings[t].append(tr[t])
                    tr3d[i].append(rings[t].index(tr[t]))
                else:
                    rings[t].append(("unk", -1))
                    tr3d[i].append(len(rings[t]) - 1)

        for t in rings:
            r = rings[t]
            tmp_len = len(r)
            for i in range(tmp_len):
                if r[i][1] == -1:
                    col = vpython.vec(0.75, 0.75, 0.75)
                elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)

col = vpython.vec(0.75, 0.75, 0.75)
                elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)
            for ip in trlst:
                vpython.cylinder(pos=start, axis=ip.pos - start, color=col, radius=0.2)  # noqa: E501
                start = ip.pos

        vpython.rate(50)

        # Keys handling
        # TODO: there is currently no way of closing vpython correctly
        # https://github.com/BruceSherwood/vpython-jupyter/issues/36
        # def keyboard_press(ev):
        #     k = ev.key
        #     if k == "esc" or k == "q":
        #         pass  # TODO: close
        #
        # vpython.scene.bind('keydown', keyboard_press)

col = vpython.vec(0.75, 0.75, 0.75)
                elif r[i][1]:
                    col = vpython.color.green
                else:
                    col = vpython.color.blue

                s = IPsphere(pos=vpython.vec((tmp_len - 1) * vpython.cos(2 * i * vpython.pi / tmp_len), (tmp_len - 1) * vpython.sin(2 * i * vpython.pi / tmp_len), 2 * t),  # noqa: E501
                             ip=r[i][0],
                             color=col)
                for trlst in six.itervalues(tr3d):
                    if t <= len(trlst):
                        if trlst[t - 1] == i:
                            trlst[t - 1] = s
        forecol = colgen(0.625, 0.4375, 0.25, 0.125)
        for trlst in six.itervalues(tr3d):
            col = vpython.vec(*next(forecol))
            start = vpython.vec(0, 0, 0)
            for ip in trlst:
                vpython.cylinder(pos=start, axis=ip.pos - start, color=col, radius=0.2)  # noqa: E501
                start = ip.pos

        vpython.rate(50)

        # Keys handling
        # TODO: there is currently no way of closing vpython correctly
        # https://github.com/BruceSherwood/vpython-jupyter/issues/36
        # def keyboard_press(ev):
        #     k = ev.key
        #     if k == "esc" or k == "q":
        #         pass  # TODO: close
        #
        # vpython.scene.bind('keydown', keyboard_press)