Python plot
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
#do not display coordinate axes
ax.set_xticks([])
ax.set_yticks([])
ax.set_zticks([])
#set title
ax.set_title("3D_Curve")
#cancel grid
ax.grid(False)
#
ax.plot(x,y,z,linestyle='',linewidth=1.2,marker='3',markersize=5, alpha=0.8, c='green')
-Common markers

-Advanced marker
For example, marker$ CircledR.

- Common colors

Draw a cube.
#cube
x,y,dx,dy,xx, yy,z,dz= 0,0,200,200,[0,0,200,200,0],[0,200,200,0,0],0,200
ax.plot(xx,yy,[z]*5,color='k',alpha=0.4)
ax.plot(xx, yy, [z+dz]*5, color='k',alpha=0.4)
ax.plot([x,x], [y,y], [z,z+dz], color='k',alpha=0.4)
ax.plot([x,x], [y+dy,y+dy], [z,z+dz], color='k',alpha=0.4)
ax.plot([x+dx,x+dx], [y+dy,y+dy], [z,z+dz], color='k',alpha=0.4)
ax.plot([x+dx,x+dx], [y,y], [z,z+dz], color='k',alpha=0.4)

Some Python minor issues:
import cv2Error: Qt. qpa. plugin: Could not load the Qt platform plugin This application failed to start because no Qt platform plugin could be initialized Reinstalling the application may fix this problem Available platform plugins are: cocoa, minimum, offscreen, webgl.
Solution: Add after cv2.
import os os.environ.pop("QT_QPA_PLATFORM_PLUGIN_PATH")