Trigonometry Circle representation using Python and Pygame
A few remarks


CIRCLE_X = int(105)
CIRCLE_Y = int(285)




Python is a duck typed language, you don't need a type in order to invoke a method or variable. You could omit the int() call here



if __name__ == '__main__':




guards, use them!



pygame.init()
pygame.display.set_caption("SineRep v. 1.0")
screen = pygame.display.set_mode((SCR_WIDTH, SCR_HEIGHT), 0, 32)
font = pygame.font.SysFont("arial",STD_FONT_SZ)
frequency = 0.1
x_txt = font.render("x", False, (0,0,0))
y_txt = font.render("y", False, (0,0,0))




These should not be global, maybe a function? def setup_game()





You have a few PEP8 violations. A good style creates more readable code :)