Determine size of string in bytes
Forgive me for this question which is most likely stupid... How do I determine the number of bytes a string takes up? I have a soap server that is returning a serialized string. It seems that when the string goes over 65978 characters it does not return to the soap client. Instead I get an error: error: (35, 'Resource temporarily unavailable') This makes me think the problem exists on the soap client side with some sort of max return length. If I knew how many bytes the 65978 character string was, then I could try to up this value. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Determine size of string in bytes
On Mar 27, 2:10 pm, John Machin [EMAIL PROTECTED] wrote: On Mar 28, 6:45 am, breal [EMAIL PROTECTED] wrote: Forgive me for this question which is most likely stupid... The contents of your question are not stupid. The subject however does invite a stupid answer like: len(the_string). Disclaimer: I know nothing about SOAP except that it's usually capitalised :-) Now read on: How do I determine the number of bytes a string takes up? I have a soap server that is returning a serialized string. Serialised how? UTF-8? Yes. I meant to include that. I did not understand that len() returned the actual byte length of a UTF-8 encoded string. It seems that when the string goes over 65978 characters it does not return to the soap client. Why does it seem so? How did you arrive at such a precise limit? I actually just wrote a test that would call a function on the SOAP server (SOAPpy) that would increase or decrease the test length based on the previous result until it found x, x+1 where x characters didn't fail, but x+1 did. x ended up being 65978. The string I happen to be encoding in this case has all ascii characters so it is the same for both encodings. Instead I get an error: error: (35, 'Resource temporarily unavailable') Is this error from the client or the server? Any error or logfile record from the other side? This is an error on the server. The client is actually written in PHP. There is no log file, but there is a traceback... Traceback (most recent call last): File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/SocketServer.py, line 464, in process_request_thread self.finish_request(request, client_address) File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/SocketServer.py, line 254, in finish_request self.RequestHandlerClass(request, client_address, self) File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/SocketServer.py, line 522, in __init__ self.handle() File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/BaseHTTPServer.py, line 316, in handle self.handle_one_request() File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/BaseHTTPServer.py, line 310, in handle_one_request method() File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/site-packages/SOAPpy/Server.py, line 545, in do_POST self.wfile.write(resp) File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/socket.py, line 262, in write self.flush() File /Library/Frameworks/Python.framework/Versions/2.5/lib/ python2.5/socket.py, line 249, in flush self._sock.sendall(buffer) error: (35, 'Resource temporarily unavailable') Is there anything in the documentation about maximum sizes? I googled my brains out looking for anything about maximum size both on the Python SOAP server, and the PHP SOAP client. This makes me think the problem exists on the soap client side with some sort of max return length. Think? Can't you verify this by inspecting the source? I haven't inspected the source, but I have inspected the documentation. No luck in finding anything about it. I suppose I could download the client source and see what I can see. If I knew how many bytes the 65978 character string was, then I could try to up this value. How do you know the string is 65978 characters? If you are debugging the server, can't you do len(serialise(the_65978_char_string))? 65978? Are you sure? Looks suspiciously close to 65535 aka 0x aka (2 ** 16 - 1 ) to me. If you have the server, you presumably have the source code for both client and server. Some options for you: (1) Look at the traceback(s), look at the source code, nut it out for yourself. If there is some kind of max other than an implicit 16-bit limitation in the client code, it shouldn't be too hard to find. (2) Post the traceback(s) here, along with other details that might be useful, like what SOAP server s/w you are using, what version of Python, what platform. See traceback above. SOAPpy Python 2.5 OSX Server Thanks for the response John. -- http://mail.python.org/mailman/listinfo/python-list
Handling locked db tables...
I have a db table that holds a list of ports. There is a column in_use that is used as a flag for whether the port is currently in use. When choosing a port the table is read and the first available port with in_use = 0 is used, updated to in_use = 1, used, then updated to in_use = 0. I am using MySQLdb and want to make sure I am locking the table when doing reads, writes, updates since there will be several instances of my program looking for available ports simultaneously. When I run a lock table mytable read I can do all of my transactions. But, when another cursor then tries to do the read I get an error unless the first process has been completed... unlocking the tables. How is this handled generally? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Handling locked db tables...
On Feb 20, 8:05 am, M.-A. Lemburg [EMAIL PROTECTED] wrote: On 2008-02-20 16:24, breal wrote: I have a db table that holds a list of ports. There is a column in_use that is used as a flag for whether the port is currently in use. When choosing a port the table is read and the first available port with in_use = 0 is used, updated to in_use = 1, used, then updated to in_use = 0. I am using MySQLdb and want to make sure I am locking the table when doing reads, writes, updates since there will be several instances of my program looking for available ports simultaneously. When I run a lock table mytable read I can do all of my transactions. But, when another cursor then tries to do the read I get an error unless the first process has been completed... unlocking the tables. How is this handled generally? This is normal database locking behavior. If you do an update to a table from one process, the updated row is locked until the transaction is committed. If another process wants to access that row (even if only indirectly, e.g. a select that does a query which includes the data from the locked row), that process reports a database lock or times out until the lock is removed by the first process. The reason is simple: you don't want the second process to report wrong data, since there's still a chance the first process might roll back the transaction. Most modern database allow row-level locking. I'm not sure whether MySQL supports this. SQLite, for example, only support table locking. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Feb 20 2008) Python/Zope Consulting and Support ...http://www.egenix.com/ mxODBC.Zope.Database.Adapter ...http://zope.egenix.com/ mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ Try mxODBC.Zope.DA for Windows,Linux,Solaris,MacOSX for free ! eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 Marc-Andre, Thanks for the reply. I understand that this is normal locking behavior. What I am looking for is a standard method to either loop the query until the table is unlocked, or put the query into some sort of queue. Basically my queries work like this. Request comes in PART I: LOCK TABLE port_usage READ; SELECT * FROM port_usage WHERE in_use = 0; Get available port UPDATE port_usage SET in_use = 1 WHERE port = available_port; UNLOCK TABLES; send request to available port and do some stuff until finished with port PART II: LOCK TABLE port_usage READ UPDATE port_usage SET in_use = 0 WHERE port = available_port; UNLOCK TABLES; Several of these *may* be happening simultaneously so when a second request comes in, and the first one has the table locked, I want to have the PART I sql still work. Any suggestions here? -- http://mail.python.org/mailman/listinfo/python-list
Re: Spawn new process - get pid
On Feb 4, 9:25 pm, Gabriel Genellina [EMAIL PROTECTED] wrote: On 4 feb, 22:21, breal [EMAIL PROTECTED] wrote: On Feb 4, 3:34 pm, Gabriel Genellina [EMAIL PROTECTED] wrote: En Mon, 04 Feb 2008 20:59:16 -0200, breal [EMAIL PROTECTED] escribió: I have a soap server written in Python that acts as an intermediary between a web service and an InDesign server. The indesign server is non-threaded, so when all instances are used up I want to create a new instance, get the pid, use the process, then kill it. Use the subprocess module:http://docs.python.org/lib/module-subprocess.html Thanks for the reply. Using subprocess.Popen I am able to get and kill the process. However, the process I am running creates another process (an instance of InDesign Server) so when I kill the first process it doesn't kill the second. Is there any way to capture both PIDs and kill them? I assume you're on *nix. Can you modify the first process? Make it a project group leader, then kill the whole group. I don't remember the details, try `man setpgrp` (or setpg?) -- Gabriel Genellina Ok, so at first I was calling a shell script that called another program to start. I have eliminated the middle-man shell script and am now calling the program directly. But here is my problem... I need the program to start fully before I go on any further so that it is available later in my script. After it is used I need to kill the pid of the program I started. So, I was trying to use my_process = subprocess.Popen([/path/to/my/program', -port, %s %port_number, -configure, conf.%s %port_number], stdout=f1) my_process.wait() child_pid = my_process.pid Is this the right way to do it? It seems to be returning a different pid for the process... so when I try to kill it I get a no such process error. Basically I have five instances of InDesign server running on various ports.. 18400 - 18404. When they are all in use, I want to start a new instance... have it fully running... then use it and kill it. Any help is appreciated. -- http://mail.python.org/mailman/listinfo/python-list
Re: Spawn new process - get pid
On Feb 4, 3:34 pm, Gabriel Genellina [EMAIL PROTECTED] wrote: En Mon, 04 Feb 2008 20:59:16 -0200, breal [EMAIL PROTECTED] escribió: I have a soap server written in Python that acts as an intermediary between a web service and an InDesign server. The indesign server is non-threaded, so when all instances are used up I want to create a new instance, get the pid, use the process, then kill it. What is the best way to do this? I don't want to replace the current process with the new one which is looks like os.exec* does. Use the subprocess module:http://docs.python.org/lib/module-subprocess.html -- Gabriel Genellina Thanks for the reply. Using subprocess.Popen I am able to get and kill the process. However, the process I am running creates another process (an instance of InDesign Server) so when I kill the first process it doesn't kill the second. Is there any way to capture both PIDs and kill them? Thanks -- http://mail.python.org/mailman/listinfo/python-list
Spawn new process - get pid
I have a soap server written in Python that acts as an intermediary between a web service and an InDesign server. The indesign server is non-threaded, so when all instances are used up I want to create a new instance, get the pid, use the process, then kill it. What is the best way to do this? I don't want to replace the current process with the new one which is looks like os.exec* does. Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Creating unique combinations from lists
I have three lists... for instance a = ['big', 'small', 'medium']; b = ['old', 'new']; c = ['blue', 'green']; I want to take those and end up with all of the combinations they create like the following lists ['big', 'old', 'blue'] ['small', 'old', 'blue'] ['medium', 'old', 'blue'] ['big', 'old', 'green'] ['small', 'old', 'green'] ['medium', 'small', 'green'] ['big', 'new', 'blue'] ['small', 'new', 'blue'] ['medium', 'new', 'blue'] ['big', 'new', 'green'] ['small', 'new', 'green'] ['medium', 'new', 'green' ] I could do nested for ... in loops, but was looking for a Pythonic way to do this. Ideas? -- http://mail.python.org/mailman/listinfo/python-list
Re: Creating unique combinations from lists
On Jan 16, 11:33 am, Reedick, Andrew [EMAIL PROTECTED] wrote: -Original Message- From: [EMAIL PROTECTED] [mailto:python- [EMAIL PROTECTED] On Behalf Of breal Sent: Wednesday, January 16, 2008 2:15 PM To: [EMAIL PROTECTED] Subject: Creating unique combinations from lists I have three lists... for instance a = ['big', 'small', 'medium']; b = ['old', 'new']; c = ['blue', 'green']; I want to take those and end up with all of the combinations they create like the following lists ['big', 'old', 'blue'] ['small', 'old', 'blue'] ['medium', 'old', 'blue'] ['big', 'old', 'green'] ['small', 'old', 'green'] ['medium', 'small', 'green'] ['big', 'new', 'blue'] ['small', 'new', 'blue'] ['medium', 'new', 'blue'] ['big', 'new', 'green'] ['small', 'new', 'green'] ['medium', 'new', 'green' ] I could do nested for ... in loops, but was looking for a Pythonic way to do this. Ideas? http://www.python.org/dev/peps/pep-0202/ Thanks for the reply. I never realized you could use list comprehension like this... AWESOME! -- http://mail.python.org/mailman/listinfo/python-list
Funny python cartoon... hope it's not a repost
http://xkcd.com/353/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Funny python cartoon... hope it's not a repost
On Dec 18, 11:56 am, Bruno Desthuilliers [EMAIL PROTECTED] wrote: Breal a écrit : http://xkcd.com/353/ Bad luck: it *is* a repost. While we're at it, did you notice the alternate text for the image ?-) Did not notice the alt text... friggin hilarious!!! -- http://mail.python.org/mailman/listinfo/python-list
Finding overlapping times...
I have a list that looks like the following [(10, 100010), (15, 17), (19, 100015)] I would like to be able to determine which of these overlap each other. So, in this case, tuple 1 overlaps with tuples 2 and 3. Tuple 2 overlaps with 1. Tuple 3 overlaps with tuple 1. In my scenario I would have hundreds, if not thousands of these ranges. Any nice pythonic way to do this? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
