arrow

def ourarrow(x, y, linestyle='solid', yaw='left', pitch='up', color='white'):
    # usually, the arrow points to the left
    horizontaldisplacement = 75
    verticaldisplacement = horizontaldisplacement
    if 'right' in yaw:
        horizontaldisplacement = horizontaldisplacement * -1
    if 'down' in pitch:
        verticaldisplacement = verticaldisplacement * -1
    plt.gca().annotate('', xy=(x, y),
                       xytext=(x + horizontaldisplacement, y + verticaldisplacement),
                       arrowprops=dict(arrowstyle = '->',
                                       linestyle=linestyle,
                                       connectionstyle = 'arc3',
                                       color=color))
    return

test

plt.imshow(a)
ourarrow(400,400)
ourarrow(400,400, yaw='right', pitch='down', color='green')
ourarrow(400,400, yaw='left', pitch='down', color='red')
ourarrow(400,400, yaw='right', pitch='up', color='blue')
plt.show()