如何保持走出圖形窗口的隨機行走場景

Question

我對python語言和編程一般都很陌生，對我一無所知。我創建了一個隨機行走場景，它在隨機方向上進行一次特定次數的步驟。我遇到的一件事情是，有時它會離開我設置的圖形窗口，我不能再看到它在哪裏。 下面是代碼：

from random import * 
from graphics import * 
from math import * 

def walker(): 
    win = GraphWin('Random Walk', 800, 800) 
    win.setCoords(-50, -50, 50, 50) 
    center = Point(0, 0) 
    x = center.getX() 
    y = center.getY() 

while True: 
    try: 
     steps = int(input('How many steps do you want to take? (Positive integer only) ')) 
     if steps > 0: 
      break 
     else: 
      print('Please enter a positive number') 
    except ValueError: 
     print('ERROR... Try again') 

for i in range(steps): 
    angle = random() * 2 * pi 
    newX = x + cos(angle) 
    newY = y + sin(angle) 
    newpoint = Point(newX, newY).draw(win) 
    Line(Point(x, y), newpoint).draw(win) 
    x = newX 
    y = newY 

walker() 

我的問題是，有沒有辦法，我可以設置圖形窗口的參數，使步行者不能窗外去了？如果它試圖，它會轉過身來嘗試另一個方向？

謝謝！

Answer 1

嘗試定義x和y的上限和下限。然後用一個while循環繼續嘗試隨機點，直到下一個點處於邊界內。

from random import * 
from graphics import * 
from math import * 

def walker(): 
    win = GraphWin('Random Walk', 800, 800) 
    win.setCoords(-50, -50, 50, 50) 
    center = Point(0, 0) 
    x = center.getX() 
    y = center.getY() 

while True: 
    try: 
     steps = int(input('How many steps do you want to take? (Positive integer only) ')) 
     if steps > 0: 
      break 
     else: 
      print('Please enter a positive number') 
    except ValueError: 
     print('ERROR... Try again') 

# set upper and lower bounds for next point 
upper_X_bound = 50.0 
lower_X_bound = -50.0 
upper_Y_bound = 50.0 
lower_Y_bound = -50.0 
for i in range(steps): 
    point_drawn = 0 # initialize point not drawn yet 
    while point_drawn == 0: # do until point is drawn 
     drawpoint = 1 # assume in bounds 
     angle = random() * 2 * pi 
     newX = x + cos(angle) 
     newY = y + sin(angle) 
     if newX > upper_X_bound or newX < lower_X_bound: 
      drawpoint = 0 # do not draw, x out of bounds 
     if newY > upper_Y_bound or newY < lower_Y_bound: 
      drawpoint = 0 # do not draw, y out of bounds 
     if drawpoint == 1: # only draw points that are in bounds 
      newpoint = Point(newX, newY).draw(win) 
      Line(Point(x, y), newpoint).draw(win) 
      x = newX 
      y = newY 
      point_drawn = 1 # set this to exit while loop 

walker()