🌐 Mailman 3 January 2009 - Python-list - python.org

Re: math module for Decimals
by Mark Dickinson Jan. 4, 2009

Jan. 4, 2009

On Jan 4, 9:52 am, "alex goretoy" <aleksandr.gore...(a)gmail.com> wrote: > Also, another reason why I'm posting to this thread. I noticed some > error/typo in line 683 of decimal.py located on public svn repo. This is > what is looks like. > > sign = 0 if _math.copysign(1.0, f) == 1.0 else 1 This line looks okay to me; can you say why you think there's a typo here? If it's the 'sign = 0' part that's bothering you, that's just a peculiarity of Decimal: the stored sign value is 0 for positive numbers, 1 for negative numbers, which I agree is a little counterintuitive. (Think of the sign as analogous to the sign *bit* in an IEEE 754 floating-point number.) Mark

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Re: deleting a method
by Ben Finney Jan. 4, 2009

Jan. 4, 2009

MRAB <google(a)mrabarnett.plus.com> writes: > Filip Gruszczyński wrote: > > Traceback (most recent call last): > > File "<stdin>", line 1, in <module> > > AttributeError: A instance has no attribute 'foo' > > > > Why is it so and how may still delete it? > > > 'a' is an instance of class A. You're trying to delete 'foo' from > the instance. To answer the second question: since ‘foo’ is an attribute of the class ‘A’, you can delete the attribute from the class. >>> class A(object): ... def foo(self): ... pass ... >>> a = A() >>> 'foo' in dir(a) True >>> del A.foo >>> 'foo' in dir(a) False -- \ “If you don't know what your program is supposed to do, you'd | `\ better not start writing it.” —Edsger W. Dijkstra | _o__) | Ben Finney

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simple turn-based multiplayer game via TCP server/client
by greywine＠gmail.com Jan. 4, 2009

Jan. 4, 2009

Hi everyone, I'm learning python to get a multiplayer roleplaying game up and running. I didn't see any simple examples of multiplayer games on the web so I thought I'd post mine here. I choose Rock, Paper, Scissors as a first game to experiment with as the game logic/options are easy to implement and understand. Initially, I tried to get the socketserver.TCPServer example in the Python Docs to work, but couldn't get my game variables into the handle method of the class MyTCPHandler. And I didn't know how else to do it. I ended up creating my own server & client out of simple sockets based on the simple echo server & client examples in the Python Docs. I also wanted to send chat messages OR game variables back & forth, but I couldn't figure out how to do the OR, so the basic idea in this implementation is to send the dictionary 'game' back and forth. game dict contains all the gaming variables as well as any chat messages. The program processes results depending on whether the game is starting, there's a chat message, or there's a game move. Finally, in testing, I ran the server in IDLE, but I had to load a command prompt and switch to c:\python30; then type 'python rpsmulti.py' for the client every time. Anyone know how to test server/client code strictly in IDLE? Anyway, try it out and let me know how you would improve it. John R. # NAME: rpsmulti.py # DESCRIPTION: rock, paper, scissors game multiplayer game # AUTHOR: John Robinson # DATE: 1/3/09 # VERSION: Python 3.0 # TO DO: # .server_address instead of HOST, PORT? import socket from random import choice from pickle import dumps, loads from pprint import pprint HOST, PORT = "localhost", 9999 # defined for now BUFFSIZE = 1024 # for socket.send & recv commands BACKLOG = 2 # number of clients supported by server SECONDS = 3 # seconds until socket.timeout (not implemented) # moves dict to translate 'rps' choice MOVES = {'r':'Rock', 'p':'Paper', 's':'Scissors'} # outcome dict stores result for all possible scenarios OUTCOME = {('p','r'): 'win', ('r','s'): 'win', ('s','p'): 'win', ('p','p'): 'draw', ('r','r'): 'draw', ('s','s'): 'draw', ('r','p'): 'lose', ('s','r'): 'lose', ('p','s'): 'lose'} def main_menu(game): """ initialize game dict variables & opening screen of the game """ game['total'] = 0 # total number of games played game['won'] = 0 # total games won by player game['lost'] = 0 # total games lost by player game['drew'] = 0 # total games drew by player game['move'] = '' # player's move (rps) game['message'] = '' # player's chat message game['sentmessage'] = '' # player's previous message game['start'] = True # setting up the game boolean print("\tROCK PAPER SCISSORS\n") if game['name']=='': # if returning to menu don't display the following game['name'] = get_name() print("Welcome "+game['name']+". Remember...") print("Rock smashes scissors! Paper covers Rock! Scissors cuts paper!\n") print("1. Play single player game") print("2. Start two player game") print("3. Join two player game") print("4. Quit") print() c = safe_input("Your choice? ", "1234") c = int(c) if c==1: one_player(game) elif c==2: start_two_player(game) elif c==3: two_player_join(game) else: print('Play again soon.') def safe_input(prompt, values='abcdefghijklmnopqrstuvwxyz'): """ gives prompt, checks first char of input, assures it meets given values default is anything goes """ while True: i = input(prompt) try: c = i[0].lower() except IndexError: # the only possible error?! if c=='': print("Try again.") else: if c not in values: # some other character print("Try again.") else: # looks good. continue. break return i def get_name(): """ returns input as name """ while True: name = input("What is your name? ") check = input(name + ". Correct (y/n)? ") if check[0] in 'yY': break return name def get_result(player, opponent): """ reports opponent's choice; checks player and opponent dicts ['move'] against OUTCOME dict; reports result returns player dict with updated values """ print(opponent['name'], 'chose %s.' % (MOVES[opponent['move']])) # check lookout dict (OUTCOME dictionary) result = OUTCOME[(player['move'], opponent['move'])] # update game variables player['total'] += 1 if result=='win': print('%s beats %s. You win.' % (MOVES[player['move']], MOVES [opponent['move']])) player['won'] += 1 elif result=='draw': print('%s - %s: no one wins. You draw.' % (MOVES[player ['move']], MOVES[opponent['move']])) player['drew'] += 1 else: print('%s loses to %s. You lose.' % (MOVES[player['move']], MOVES[opponent['move']])) player['lost'] += 1 return player def one_player(game): """ implements one player game with minimal opponent dict """ print("\nType (R)ock, (P)aper or (S)cissors to play. (q)uit to return to \ main menu.") opponent = {} opponent['name'] = 'Computer' # gaming loop while True: # gets player's choice game['move'] = safe_input('1, 2, 3, GO! ','rpsq') if game['move']=='q': break # computer chooses via random.choice opponent['move'] = choice('rps') # check game outcome dict game = get_result(game, opponent) # exit loop print('\nYou won %s, lost %s, drew %s (%s total)\n' % \ (game['won'],game['lost'],game['drew'],game['total'])) main_menu(game) def start_two_player(game): """ starts tcp server and implements two player game game dict = player 1""" # Create a socket (SOCK_STREAM means a TCP socket) sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.bind((HOST, PORT)) sock.listen(BACKLOG) serverip, serverport = sock.getsockname() print("Running at %s, %s" % (serverip, serverport)) print("\nType (R)ock, (P)aper or (S)cissors to play. (q)uit to \ return to main menu.") print("Waiting for player...") client, address = sock.accept() clientip, clientport = address # server/game loop while True: try: P2game = loads(client.recv(BUFFSIZE)) # receive other game variables except EOFError: # if available print(P2game['name'], "left the game.") break client.send(dumps(game)) # send our variables # it's either the start... if P2game['start']: print(P2game['name'],"logged on at", clientip, clientport) game['start'] = False # or there's a message if P2game['message']!='' and P2game['message']!=game ['sentmessage']: print(P2game['name']+': '+P2game['message']) game['sentmessage'] = P2game['message'] # to avoid many print calls game['move'] = '' # message always takes priority # or there's a move if game['move']=='': game['move'] = safe_input('1, 2, 3, GO! ') if game['move']=='q': break elif game['move'] not in 'rps': game['message'] = game['move'] game['move'] = '' # only check result if P2game also made a move if P2game['move']!='': # check game outcome dict game=get_result(game, P2game) game['move']='' # exit loop client.close() print('\nYou won %s, lost %s, drew %s (%s total)\n' % \ (game['won'],game['lost'],game['drew'],game['total'])) main_menu(game) def two_player_join(game): """ joins a tcp server two player game game dict = player 2""" # Create a socket (SOCK_STREAM means a TCP socket) sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((HOST, PORT)) print("\nType (R)ock, (P)aper or (S)cissors to play. (q)uit to \ return to main menu.") # client/game loop while True: sock.send(dumps(game)) try: P1game = loads(sock.recv(BUFFSIZE)) except EOFError: print(P1game['name'], "left the game.") break if P1game['start']: print("You're connected to "+P1game['name']+"'s game.") game['start'] = False if P1game['message']!='' and P1game['message']!=game ['sentmessage']: print(P1game['name']+': '+P1game['message']) game['sentmessage'] = P1game['message'] game['move'] = '' if game['move']=='': game['move'] = safe_input('1, 2, 3, GO! ') if game['move']=='q': break elif game['move'] not in 'rps': game['message'] = game['move'] game['move'] = '' if P1game['move']!='': # check game outcome dict game=get_result(game, P1game) game['move']='' # exit loop sock.close() print('\nYou won %s, lost %s, drew %s (%s total)\n' % \ (game['won'],game['lost'],game['drew'],game['total'])) main_menu(game) if __name__=='__main__': game = {} # initialize game dict to store all game variables game['name'] = '' # player's name initially main_menu(game)

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Port of python stdlib to other languages.
by vk Jan. 4, 2009

Jan. 4, 2009

Have there been ports of the Python standard library to other languages? I would imagine using pickle, urllib, and sys in C (with pythonic naming conventions) would be easier than using other libraries to do the same thing.

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Doubt on creating threads
by koranthala＠gmail.com Jan. 4, 2009

Jan. 4, 2009

I was going through Python posts and this post caught my attention http://groups.google.com/group/comp.lang.python/browse_thread/thread/f99326… <quote> You have missed an important point. A well designed application does neither create so many threads nor processes. The creation of a thread or forking of a process is an expensive operation. You should use a pool of threads or processes. </unquote> I am creating an application and it creates ~1-2 threads every second and kill it within 10 seconds. After reading this I am worried. Is creating a thread a very costly operation? I cannot use a pool of threads because I am using an external application (twisted) to create the threads (deferToThread).

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win32gui
by Gandalf Jan. 4, 2009

Jan. 4, 2009

Hi, I'm trying to capture the text word under the user cursor, so I was searching the win32 lib for functions I can use. i used this to fined the controller under the cursor win32gui.WindowFromPoint(win32gui.GetCursorPos()) to get the controller, but then when I try to read the text with this GetWindowText function it most of the time doesn't work, all the "getline" methon like the following didn't worked in most of the time too win32gui.SendMessage(hwnd, win32con.EM_GETLINE, line, linetext) I found this GetCharFromPosition in a VB forum which sound promising but unfortunately it's not part of the win32gui for python so now i'm looking for a reliable way to rich text from a controller or position if you know a function who may do it or a better way please tell me/ thank you and have a nice day

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strange behavior of math.sqrt() in new 3.0 version
by David Lemper Jan. 4, 2009

Jan. 4, 2009

I'm a newbee trying 3.0 Please help with math.sqrt() At the command line this function works correctly >>> import math n = input("enter a number > ") s = math.sqrt(n) An entry of 9 or 9.0 will yield 3.0 Yet the same code in a script gives an error message Script1 import math n = input("enter a number > ") s = math.sqrt(n) Traceback (most recent call last) : File "<stdin>", line 1, in <module> File "script1.py" line 3 in <module> s = math.sqrt(n) TypeError : a float is required Entering 9 or 9.0 gives same error message. According to the math module the results of all functions are floats. However it says nothing about inputs. Strangely the above code runs fine in version 2.5 ( ? ) and will handle large integers. I've read the documentation for 3.0 including the section "Floating Point Arithmetic: Issues & Limitations" and it helps nada.

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Re: Noob question: Is all this typecasting normal?
by Steven D'Aprano Jan. 4, 2009

Jan. 4, 2009

On Sat, 03 Jan 2009 20:35:25 +0000, alex goretoy wrote: > for each his own. Please don't top-post. Please don't quote the ENTIRE body of text (PLUS doubling it by including a completely useless HTML version) just to add a trivial comment. Trim the text you are replying to. > Any more word on userio? I doubt many people care about it. Why don't you write it, put it up on the Cheeseshop, and see if anyone uses it? Just because you think it is useful doesn't mean others do, but if they do, then great. -- Steven

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Re: select.select and socket.setblocking
by Bryan Olson Jan. 3, 2009

Jan. 3, 2009

Laszlo Nagy wrote: [...] > I have read the socket programming howto ( > http://docs.python.org/howto/sockets.html#sockets ) but it does not > explain how a blocking socket + select is different from a non blocking > socket + select. Is there any difference? There is, but it may not effect you. There are cases where a socket can select() as readable, but not be readable by the time of a following recv() or accept() call. All such cases with which I'm familiar call for a non-blocking socket. Where does this come up? Suppose that to take advantage of multi-core processors, our server runs as four processes, each with a single thread that responds to events via select(). Clients all connect to the same server port, so the socket listening on that port is shared by all four processes. A perfectly reasonable architecture (though with many more processes the simple implementation suffers the "thundering herd problem"). Two of our processors may be waiting on select() when a new connections comes in. The select() call returns in both processes, showing the socket ready for read, so both call accept() to complete the connection. The O.S. ensures that accept() [and recv()] are atomic, so one process gets the new connection; what happens in the other depends on whether we use a blocking or non-blocking socket, and clearly we want non-blocking. -- --Bryan

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Re: ResponseNotReady exception
by asit Jan. 3, 2009

Jan. 3, 2009

On Jan 4, 1:59 am, "Chris Rebert" <c...(a)rebertia.com> wrote: > On Sat, Jan 3, 2009 at 12:38 PM, asit <lipu...(a)gmail.com> wrote: > > import httplib > > > class Server: > > #server class > > def __init__(self, host): > > self.host = host > > def fetch(self, path): > > http = httplib.HTTPConnection(self.host) > > http.putrequest("GET", path) > > According to the docs, if you use .putrequest(), you have to also then > call .putheader() [as many times as necessary], .endheaders(), and > .send(), in that order. I'd advise just changing .putrequest() to > .request() instead. > > And you should also read the fine docs yourself:http://docs.python.org/library/httplib.html > > Cheers, > Chris > > -- > Follow the path of the Iguana...http://rebertia.com Thanx

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