Generate n random particles with random velocity vectors in python using curses

random_particles.py

import curses
from time import time,sleep
from random import randrange,random
from math import cos,sin,pi
import argparse

class TUI:
	FPS=60

	def __init__(self,screen,no_particles):
		self.screen=screen
		
		self.particles=[Particle(screen,"🥺") for _ in range(no_particles)]

		screen.clear()
		screen.nodelay(True)
		curses.curs_set(0)
		self.__quit=False

	def update(self,char):
		{
			ord("q"):self.quit,
			ord("Q"):self.quit
		}.get(char,lambda:None)()
		for particle in self.particles:particle.update()

	def quit(self):
		self.__quit=True

	def run(self):
		while self.__quit!=True:
			self.screen.erase()
			start=time()
			self.update(self.screen.getch())
			self.screen.refresh()
			sleep(max(0,1/TUI.FPS - (time()-start)))

class Particle:
	VELOCITY=.5
	
	def __init__(self,screen,msg):
		self.screen=screen
		self.msg=msg
		heigth,width=screen.getmaxyx()
		self.x=float(randrange(width-2))
		self.y=float(randrange(heigth-1))
		theta=random()*pi
		self.vx=cos(theta)
		self.vy=sin(theta)

	def update(self):
		self.screen.addstr(int(self.y),int(self.x),self.msg)
		
		heigth,width=self.screen.getmaxyx()

		dx=self.vx*Particle.VELOCITY
		dy=self.vy*Particle.VELOCITY

		if not (1<=int(self.x+dx)<(width-2)):
			self.vx*=-1
			dx*=-1
		if not (1<=int(self.y+dy)<heigth):
			self.vy*=-1
			dy*=-1
		
		self.x+=dx
		self.y+=dy

if __name__=="__main__":
	parser=argparse.ArgumentParser()
	parser.add_argument("no_particles",type=int)
	args=parser.parse_args()
	curses.wrapper(lambda screen:TUI(screen,args.no_particles).run())