Fixed speed issue, no longer load each subreddit just to get the url.

examples/life.py

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+#!/usr/bin/env python
+# life.py -- A curses-based version of Conway's Game of Life.
+# Contributed by AMK
+#
+# An empty board will be displayed, and the following commands are available:
+#  E : Erase the board
+#  R : Fill the board randomly
+#  S : Step for a single generation
+#  C : Update continuously until a key is struck
+#  Q : Quit
+#  Cursor keys :  Move the cursor around the board
+#  Space or Enter : Toggle the contents of the cursor's position
+#
+# TODO :
+#   Support the mouse
+#   Use colour if available
+#   Make board updates faster
+#
+
+import random, string, traceback
+import curses
+
+class LifeBoard:
+    """Encapsulates a Life board
+
+    Attributes:
+    X,Y : horizontal and vertical size of the board
+    state : dictionary mapping (x,y) to 0 or 1
+
+    Methods:
+    display(update_board) -- If update_board is true, compute the
+                             next generation.  Then display the state
+                             of the board and refresh the screen.
+    erase() -- clear the entire board
+    makeRandom() -- fill the board randomly
+    set(y,x) -- set the given cell to Live; doesn't refresh the screen
+    toggle(y,x) -- change the given cell from live to dead, or vice
+                   versa, and refresh the screen display
+
+    """
+    def __init__(self, scr, char=ord('*')):
+        """Create a new LifeBoard instance.
+
+        scr -- curses screen object to use for display
+        char -- character used to render live cells (default: '*')
+        """
+        self.state = {}
+        self.scr = scr
+        Y, X = self.scr.getmaxyx()
+        self.X, self.Y = X-2, Y-2-1
+        self.char = char
+        self.scr.clear()
+
+        # Draw a border around the board
+        border_line = '+'+(self.X*'-')+'+'
+        self.scr.addstr(0, 0, border_line)
+        self.scr.addstr(self.Y+1,0, border_line)
+        for y in range(0, self.Y):
+            self.scr.addstr(1+y, 0, '|')
+            self.scr.addstr(1+y, self.X+1, '|')
+        self.scr.refresh()
+
+    def set(self, y, x):
+        """Set a cell to the live state"""
+        if x<0 or self.X<=x or y<0 or self.Y<=y:
+            raise ValueError, "Coordinates out of range %i,%i"% (y,x)
+        self.state[x,y] = 1
+
+    def toggle(self, y, x):
+        """Toggle a cell's state between live and dead"""
+        if x<0 or self.X<=x or y<0 or self.Y<=y:
+            raise ValueError, "Coordinates out of range %i,%i"% (y,x)
+        if self.state.has_key( (x,y) ):
+            del self.state[x,y]
+            self.scr.addch(y+1, x+1, ' ')
+        else:
+            self.state[x,y] = 1
+            self.scr.addch(y+1, x+1, self.char)
+        self.scr.refresh()
+
+    def erase(self):
+        """Clear the entire board and update the board display"""
+        self.state = {}
+        self.display(update_board=False)
+
+    def display(self, update_board=True):
+        """Display the whole board, optionally computing one generation"""
+        M,N = self.X, self.Y
+        if not update_board:
+            for i in range(0, M):
+                for j in range(0, N):
+                    if self.state.has_key( (i,j) ):
+                        self.scr.addch(j+1, i+1, self.char)
+                    else:
+                        self.scr.addch(j+1, i+1, ' ')
+            self.scr.refresh()
+            return
+
+        d = {}
+        self.boring = 1
+        for i in range(0, M):
+            L = range( max(0, i-1), min(M, i+2) )
+            for j in range(0, N):
+                s = 0
+                live = self.state.has_key( (i,j) )
+                for k in range( max(0, j-1), min(N, j+2) ):
+                    for l in L:
+                        if self.state.has_key( (l,k) ):
+                            s += 1
+                s -= live
+                if s == 3:
+                    # Birth
+                    d[i,j] = 1
+                    self.scr.addch(j+1, i+1, self.char)
+                    if not live: self.boring = 0
+                elif s == 2 and live: d[i,j] = 1       # Survival
+                elif live:
+                    # Death
+                    self.scr.addch(j+1, i+1, ' ')
+                    self.boring = 0
+        self.state = d
+        self.scr.refresh()
+
+    def makeRandom(self):
+        "Fill the board with a random pattern"
+        self.state = {}
+        for i in range(0, self.X):
+            for j in range(0, self.Y):
+                if random.random() > 0.5:
+                    self.set(j,i)
+
+
+def erase_menu(stdscr, menu_y):
+    "Clear the space where the menu resides"
+    stdscr.move(menu_y, 0)
+    stdscr.clrtoeol()
+    stdscr.move(menu_y+1, 0)
+    stdscr.clrtoeol()
+
+def display_menu(stdscr, menu_y):
+    "Display the menu of possible keystroke commands"
+    erase_menu(stdscr, menu_y)
+    stdscr.addstr(menu_y, 4,
+                  'Use the cursor keys to move, and space or Enter to toggle a cell.')
+    stdscr.addstr(menu_y+1, 4,
+                  'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit')
+
+def keyloop(stdscr):
+    # Clear the screen and display the menu of keys
+    stdscr.clear()
+    stdscr_y, stdscr_x = stdscr.getmaxyx()
+    menu_y = (stdscr_y-3)-1
+    display_menu(stdscr, menu_y)
+
+    # Allocate a subwindow for the Life board and create the board object
+    subwin = stdscr.subwin(stdscr_y-3, stdscr_x, 0, 0)
+    board = LifeBoard(subwin, char=ord('*'))
+    board.display(update_board=False)
+
+    # xpos, ypos are the cursor's position
+    xpos, ypos = board.X//2, board.Y//2
+
+    # Main loop:
+    while (1):
+        stdscr.move(1+ypos, 1+xpos)     # Move the cursor
+        c = stdscr.getch()                # Get a keystroke
+        if 0<c<256:
+            c = chr(c)
+            if c in ' \n':
+                board.toggle(ypos, xpos)
+            elif c in 'Cc':
+                erase_menu(stdscr, menu_y)
+                stdscr.addstr(menu_y, 6, ' Hit any key to stop continuously '
+                              'updating the screen.')
+                stdscr.refresh()
+                # Activate nodelay mode; getch() will return -1
+                # if no keystroke is available, instead of waiting.
+                stdscr.nodelay(1)
+                while (1):
+                    c = stdscr.getch()
+                    if c != -1:
+                        break
+                    stdscr.addstr(0,0, '/')
+                    stdscr.refresh()
+                    board.display()
+                    stdscr.addstr(0,0, '+')
+                    stdscr.refresh()
+
+                stdscr.nodelay(0)       # Disable nodelay mode
+                display_menu(stdscr, menu_y)
+
+            elif c in 'Ee':
+                board.erase()
+            elif c in 'Qq':
+                break
+            elif c in 'Rr':
+                board.makeRandom()
+                board.display(update_board=False)
+            elif c in 'Ss':
+                board.display()
+            else: pass                  # Ignore incorrect keys
+        elif c == curses.KEY_UP and ypos>0:            ypos -= 1
+        elif c == curses.KEY_DOWN and ypos<board.Y-1:  ypos += 1
+        elif c == curses.KEY_LEFT and xpos>0:          xpos -= 1
+        elif c == curses.KEY_RIGHT and xpos<board.X-1: xpos += 1
+        else:
+            # Ignore incorrect keys
+            pass
+
+
+def main(stdscr):
+    keyloop(stdscr)                    # Enter the main loop
+
+
+if __name__ == '__main__':
+    curses.wrapper(main)