Python Endless Looping

I have following code below:

for i in range(N):

    # Dispersed Source
    theta = np.random.uniform(0, np.pi, 1)
    phi = np.random.uniform(0, 2 * np.pi, 1)
    R = np.random.uniform(0, Ro, 1)

    x = R * np.sin(theta) * np.cos(phi)
    y = R * np.sin(theta) * np.sin(phi)  # ?
    z = R * np.cos(theta)

    x_vec, y_vec, z_vec, nu = particle_func(x, y, z)

    particle_trace = go.Scatter3d(
                        x=x_vec,
                        y=y_vec,
                        z=z_vec,
                        mode='lines'
                    )

    data.append(particle_trace)

    for j in range(int(nu)):
        x = x_vec[-1]
        y = y_vec[-1]
        z = z_vec[-1]

        x_vec_1, y_vec_1, z_vec_1, nu1 = particle_func(x, y, z)

        particle_trace_fiss = go.Scatter3d(
            x=x_vec_1,
            y=y_vec_1,
            z=z_vec_1,
            mode='lines'
        )

        data.append(particle_trace_fiss)

The problem is that the for loop needs to keep going as such:

for j in range(int(nu)):
        x = x_vec[-1]
        y = y_vec[-1]
        z = z_vec[-1]

        x_vec_1, y_vec_1, z_vec_1, nu1 = particle_func(x, y, z)

        particle_trace_fiss = go.Scatter3d(
            x=x_vec_1,
            y=y_vec_1,
            z=z_vec_1,
            mode='lines'
        )

        data.append(particle_trace_fiss)

 for k in range(int(nu1)):
        x = x_vec_1[-1]
        y = y_vec_1[-1]
        z = z_vec_1[-1]

        x_vec_2, y_vec_2, z_vec_2, nu2 = particle_func(x, y, z)

        particle_trace_fiss = go.Scatter3d(
            x=x_vec_2,
            y=y_vec_2,
            z=z_vec_2,
            mode='lines'
        )

        data.append(particle_trace_fiss)

 for l in range(int(nu2)):
        x = x_vec_2[-1]
        y = y_vec_2[-1]
        z = z_vec_2[-1]

        x_vec_3, y_vec_3, z_vec_3, nu3 = particle_func(x, y, z)

        particle_trace_fiss = go.Scatter3d(
            x=x_vec_3,
            y=y_vec_3,
            z=z_vec_3,
            mode='lines'
        )

        data.append(particle_trace_fiss)

...

Because the value of nu is a random number or zero meaning that the number of loops could potentially go on forever. This implies, to me, that a while loop must be used but I'm not sure how I would implement this. I am not looking for a specific output per se, just that each x, y, and z vector "traces" are appended to the data.

Apologies if I missing clarity in my question, I will be happy to respond to any comments requesting clarification. All help is appreciated in advance, thanks!!