def _plot_sensors(pos_x, pos_y, sensors, ax):
    from matplotlib.patches import Circle
    if sensors is True:
        for x, y in zip(pos_x, pos_y):
            ax.add_artist(Circle(xy=(x, y), radius=0.003, color='k'))
    else:
        ax.plot(pos_x, pos_y, sensors)
Aux function
dataset/ETHPy150Open mne-tools/mne-python/mne/viz/topomap.py/_plot_sensors