Pygame rotate line delete old line - python-2.7

Question

How can I rotate a line in pygame using math module and every second rotate line delete old line. I've just used other code but the problem was old line rotate and so I watched an sunshine effect.

Answer 1

To easily assist you with a specific answer for your problem, you really need to show your code. Please see how to ask.
I've prepared a generic example that randomises one end point of a line when a mouse button is clicked.
# pyg_line_demo
import pygame
import random
def get_random_position():
"""return a random (x,y) position in the screen"""
return (random.randint(0, screen_width - 1), #randint includes both endpoints.
random.randint(0, screen_height - 1))
def random_line(line):
""" Randomise an end point of the line"""
if random.randint(0,1):
return [line[0], get_random_position()]
else:
return [get_random_position(), line[-1]]
# initialisation
pygame.init()
screen_width, screen_height = 640, 480
surface = pygame.display.set_mode((screen_width,screen_height))
pygame.display.set_caption('Lines')
clock = pygame.time.Clock() #for limiting FPS
FPS = 30
# initial line
line = [(10, 10), (200, 200)]
finished = False
while not finished:
for event in pygame.event.get():
if event.type == pygame.QUIT:
finished = True
if event.type == pygame.MOUSEBUTTONDOWN:
line = random_line(line)
#redraw background
surface.fill(pygame.Color("white"))
#draw line
pygame.draw.aalines(surface, pygame.Color("blue"), False, line)
# update display
pygame.display.update()
#limit framerate
clock.tick(FPS)
pygame.quit()
You should be able to insert your line rotation function in place of the random_line() function.
Let us know if you have any further questions.