Re: Python for philosophers
Maybe the implementation of the Python Interpreter could be seen as transition function. This can be understand in detail, but it even if you know how the interpreter works, you don't really know to work _with_ the interpreter. Even more, there are a lot of decisions, which are made 'by design' and don't have a clear answer. to see why somethings are done in the way they are done you have to understand the philosophy of programming with python. bg, Johannes On 13.05.2013 02:34, Gregory Ewing wrote: Citizen Kant wrote: What I do here is to try to "understand". That's different from just knowing. Knowledge growth must be consequence of understanding's increasing. As the scope of my understanding increases, the more I look for increasing my knowledge. Never vice versa, because, knowing isn't like to be right, it's just knowing. It doesn't always work that way. With some facts plus a theory, you can deduce more facts. But it's always possible for there to be more facts that you can't deduce from what you already know. But take in account that with "shortening" I refer to "according to Python's axiomatic parameters". I think what you're trying to say is that it takes an expression and reduces it to a canonical form, such as a single number or single string. That's true as far as it goes, but it barely scratches the surface of what the Python interpreter is capable of doing. In the most general terms, the Python interpeter (or any other computer system, for that matter) can be thought of as something with an internal state, and a transition function that takes the state together with some input and produces another state together with some output: F(S1, I) --> (S2, O) (Computer scientists call this a "finite state machine", because there is a limited number of possible internal states -- the computer only has so much RAM, disk space, etc.) This seems to be what you're trying to get at with your game-of-chess analogy. What distinguishes one computer system from another is the transition function. The transition function of the Python interpreter is rather complicated, and it's unlikely that you would be able to figure out all its details just by poking in inputs and observing the outputs. If you really want to understand it, you're going to have to learn some facts, I'm sorry to say. :-) -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
serialize a class to XML and back
Hi list, how can I serialize a python class to XML? Plus a way to get the class back from the XML? My aim is to store instances of this class in a database. bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: serialize a class to XML and back
On 26.05.2013 22:48, Roy Smith wrote: In article , Chris Rebert wrote: On May 23, 2013 3:42 AM, "Schneider" wrote: Hi list, how can I serialize a python class to XML? Plus a way to get the class back from the XML? There's pyxser: http://pythonhosted.org/pyxser/ My aim is to store instances of this class in a database. Honestly, I would avoid XML if you can. Consider using JSON (Python includes the `json` module in the std lib) or pickle instead. Compared to XML: The former is more standardized (in the context of serializing objects) and less verbose; the latter is more efficient (if you don't care about cross-language accessibility); both have more convenient APIs. Some other points... If you care about efficiency and want to use json, don't use the one that comes packaged with the standard library. There are lots of third-party json packages (ujson is the one we use) which are significantly faster. Not sure if that's true of the newest python releases, but it was certainly true in 2.6. I think performance can be a problem in future. This question is part of a multi-user rss-reader solution, which I'm going to develop. I want to store the feed entries (+ some additional data) as XML in a database. The advantage of pickle over json is that pickle can serialize many types of objects that json can't. The other side of the coin is that pickle is python-specific, so if you think you'll ever need to read your data from other languages, pickle is right out. -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: serialize a class to XML and back
On 25.05.2013 07:54, dieter wrote: Schneider writes: how can I serialize a python class to XML? Plus a way to get the class back from the XML? My aim is to store instances of this class in a database. In case you want to describe the XML data via an XML-schema (e.g. to exchange it with other applications; maybe via WebServices), you may have a look at "PyXB". The approach of "PyXB" may be a bit different from yours: It starts with an XML-schema description and from it generates Python classes corresponding to the types mentioned in the schema. Instances of those classes can then be easily serialized to XML and XML documents corresponding to types defined in the schema can easily be converted into corresponding class instances. It is not too difficult to customize the classes used for a given type - e.g. to give them special methods related to your application. You may want to start with your (arbitrary) Python classes and get their instances serialized into an adequate XML document. This will not work in all cases: some things are very difficult to serialize (maybe even not serializable at all - e.g. locks). I have just small classes containing text (strings) numbers (as ids) and references to other classes of this type. If you plan to use anything already existing, then almost surely, this will impose restrictions of your classes. -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: Critic my module
Hi, nice idea. mybe - for security reasons - you should ensure, that the right tool is called and not some tool put the path with the same name. bg, Johannes On Thu 25 Jul 2013 03:24:30 PM CEST, Devyn Collier Johnson wrote: Aloha Python Users! I made a Python3 module that allows users to use certain Linux shell commands from Python3 more easily than using os.system(), subprocess.Popen(), or subprocess.getoutput(). This module (once placed with the other modules) can be used like this import boash; boash.ls() I attached the module. I plan to release it on the Internet soon, but feel free to use it now. It is licensed under LGPLv3. The name comes from combining "Boa" with "SHell". Notice that the module's name almost looks like "BASH", a common Linux shell. The Boa is a constrictor snake. This module makes Unix shells easier to use via Python3. This brings the system shell closer to the Python shell. Mahalo, Devyn Collier Johnson devyncjohn...@gmail.com -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: Critic my module
Hi, lets uses the ls example: the way you do it now implies, that you search your PATH variable until it finds a program called 'ls'. So if we are able to change the PATH variable, and put out own 'ls' somewhere in the (new) paths, calling you ls() will execute whatever we want our own ls' to do. Second remark: if the behavior of some tools is changed (for examples with using aliases) we cannot expect the called tool (in the example: 'ls') to give the same output on every system. this can be avoided (mostly) by ensuring that the right program (in the example /bin/ls) is called, and not only ls. bg, Johannes On 07/26/2013 12:39 PM, Devyn Collier Johnson wrote: On 07/25/2013 09:58 AM, Schneider wrote: Hi, nice idea. mybe - for security reasons - you should ensure, that the right tool is called and not some tool put the path with the same name. bg, Johannes Devyn Collier Johnson On Thu 25 Jul 2013 03:24:30 PM CEST, Devyn Collier Johnson wrote: Aloha Python Users! I made a Python3 module that allows users to use certain Linux shell commands from Python3 more easily than using os.system(), subprocess.Popen(), or subprocess.getoutput(). This module (once placed with the other modules) can be used like this import boash; boash.ls() I attached the module. I plan to release it on the Internet soon, but feel free to use it now. It is licensed under LGPLv3. The name comes from combining "Boa" with "SHell". Notice that the module's name almost looks like "BASH", a common Linux shell. The Boa is a constrictor snake. This module makes Unix shells easier to use via Python3. This brings the system shell closer to the Python shell. Mahalo, Devyn Collier Johnson devyncjohn...@gmail.com -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 What do you mean by that Schneider? Mahalo, Devyn Collier Johnson devyncjohn...@gmail.com -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: Lambda function Turing completeness
On Wed 31 Jul 2013 08:53:26 AM CEST, Musical Notation wrote: Is it possible to write a Turing-complete lambda function (which does not depend on named functions) in Python? what should a sinlge Turing-complete lambda function be? For me, a programming language can be Turing-complete or a function can be universal, e.g. like an interpreter for a programming language. bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
SSH Connection with Python
Hi Folkz, how can i create a SSH-Connection with python? I have to send some commands to the remote host and parse their answers. greatz Johannes -- http://mail.python.org/mailman/listinfo/python-list
Re: SSH Connection with Python
thank you guys for the huge list of answers, In my setting I have to access some routers and firewall from a linux-client. I think I'll try Fabric. On 26.10.2012 06:20, Rodrick Brown wrote: On Oct 25, 2012, at 6:34 AM, Schneider wrote: Hi Folkz, how can i create a SSH-Connection with python? I have to send some commands to the remote host and parse their answers. greatz Johannes Fabric is the way to go! -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Python performance
Hi list, I have to write a small SMTP-Relay script (+ some statistic infos) and I'm wondering, if this can be done in python (in terms of performance, of course not in terms of possibility ;) ). It has to handle around 2000 mails per hour for at least 8hours a day (which does not mean, that it is allowed not to respond the rest of the day. Can this be done? or should I better use some other programming language? My second choice would be erlang. bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsber ger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: Python performance
On Fri 02 Aug 2013 02:59:26 PM CEST, Tim Chase wrote: On 2013-08-02 14:00, Schneider wrote: I have to write a small SMTP-Relay script (+ some statistic infos) and I'm wondering, if this can be done in python (in terms of performance, of course not in terms of possibility ;) ). It has to handle around 2000 mails per hour for at least 8hours a day (which does not mean, that it is allowed not to respond the r est of the day. Can this be done? or should I better use some other programming language? My second choice would be erlang. I suspect it depends on a lot of factors: - will your network connection support that much traffic? (And an ISP that will grant you permission to spew that volume of email?) yes, because we are the ISP. - are these simple text emails, or are they large with lots of attachments, inline images, PDFs, or whatever? any kind of mail. No restrictions allowed. - are the statistics that you're gathering simple, or do they require complex analysis of the documents passing through? very simple statistics, mostly counting and time statistics. - is the load 8hr straight of spewing email, or is it bursty? If it's bursty, you can internally queue them up when load gets high, delivering them from that queue when load diminishes. Given the store-and-forward nature of email, there's no guarantee that if you spewe d them at ~33/minute (that/s a little faster than one every two seconds), they'd arrive at their destination any faster than if you'd queued them up and sent them at a more steady rate. I guess it's bursty. I don't have finer granulated information about their time distribution. -tkc Queuing the mails for a while is not possible, because the tool should sit between the client and smtp-server. It should act as proxy, not as server. bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Re: Python performance
On 08/02/2013 03:09 PM, Ray Cote wrote: - Original Message - From: "Schneider" To: python-list@python.org Sent: Friday, August 2, 2013 8:00:09 AM Subject: Python performance Hi list, I have to write a small SMTP-Relay script (+ some statistic infos) and I'm wondering, if this can be done in python (in terms of performance, of course not in terms of possi bility ;) ). It has to handle around 2000 mails per hour for at least 8hours a day (which does not mean, that it is allowed not to respond the rest of the day. A quick calculation shows that 2,000 mails per hour is less than 1 email every second. Plenty of time to handle individual emails. This is just true, if the mails arrive equally distributed. We cannot ensure this. -- http://mail.python.org/mailman/listinfo/python-list
Re: What minimum should a person know before saying "I know Python"
I would say it's a little bit more: You have to know the keywords and (basic) concepts, e.g. you really have to understand what it means, that everything is a class. If you get foreign, you have to be able to understand it. And the other way round, given a problem, you should be able to write a working solution. bg Johannes On 09/20/2013 06:23 PM, Mark Janssen wrote: I started Python 4 months ago. Largely self-study with use of Python documentation, stackoverflow and google. I was thinking what is the minimum that I must know before I can say that I know Python? Interesting. I would say that you must know the keywords, how to make a Class, how to write a loop. That covers about 85% of it. -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- https://mail.python.org/mailman/listinfo/python-list
Good Python Book
Hi List, I'm looking for a good advanced python book. Most books I looked at up to now are on beginners level. I don't need a reference (that's online) or a book explaining how to use the interpreter or how to use list comprehensions on the one side and skipping topics like decorators, metaclasses on the other side. any suggestions? bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- https://mail.python.org/mailman/listinfo/python-list
Re: Debugging decorator
On 10/26/2013 01:55 AM, Yaşar Arabacı wrote: Hi people, I wrote this decorator: https://gist.github.com/yasar11732/7163528 When this code executes: @debugging def myfunc(a, b, c, d = 48): a = 129 return a + b print myfunc(12,15,17) This is printed: function myfunc called a 12 c 17 b 15 d 48 assigned new value to a: 129 returning 144 144 I think I can be used instead of inserting and deleting print statements when trying to see what is passed to a function and what is assingned to what etc. I think it can be helpful during debugging. It works by rewriting ast of the function and inserting print nodes in it. What do you think? Looks very nice, but I've three questions: 1. What happens, if a function has more then one decorator? Wouldn't it be better to just remove the debugging decorator instead of removing all decorators? 2. In the case of an assignment (but holds for the return statement too). think about the following code: a = 0 @debugging def foo(): a = a + 1 def bar(): #assign something else to a Imagine foo() and bar() being called in two different threads. Wouldn't it be better to replace a = a + 1 by |global_debugging_lock_objekt.acquire()| a = a + 1 print "assigned new value to a, %r", a |global_debugging_lock_objekt.release()| for some global lock object. 3. What happens in the case of a += 1? bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- https://mail.python.org/mailman/listinfo/python-list
Re: Creating an object that can track when its attributes are modified
Hi, maybe you could do this by a decorator on the setattr method. It should look more or less like your implementation, but in my eyes it's a cleaner and can be reused. Further, I would use a stack for each attribute, so that you can restore all previous values. bg, Johannes On 03/06/2013 05:07 PM, Ben Sizer wrote: I am trying to make an object that can track when its attributes have been assigned new values, and which can rollback to previous values where necessary. I have the following code which I believe works, but would like to know if there are simpler ways to achieve this goal, or if there are any bugs I haven't seen yet. class ChangeTrackingObject(object): def __init__(self): self.clean() def clean(self): """Mark all attributes as unmodified.""" object.__setattr__(self, '_dirty_attributes', dict()) def dirty_vals(self): """Returns all dirty values.""" return dict( [ (k,v) for k,v in self.__dict__.iteritems() if k in self._dirty_attributes] ) def get_changes_and_clean(self): """Helper that collects all the changes and returns them, cleaning the dirty flags at the same time.""" changes = self.dirty_vals() self.clean() return changes def rollback(self): """Reset attributes to their previous values.""" for k,v in self._dirty_attributes.iteritems(): object.__setattr__(self, k, v) self.clean() def __setattr__(self, key, value): # If the first modification to this attribute, store the old value if key not in self._dirty_attributes: if key in self.__dict__: self._dirty_attributes[key] = object.__getattribute__(self, key) else: self._dirty_attributes[key] = None # Set the new value object.__setattr__(self, key, value) I am aware that adding a new attribute and then calling rollback() leaves the new attribute in place with a None value - maybe I can use a special DeleteMe marker object in the _dirty_attributes dict along with a loop that calls delattr on any attribute that has that value after a rollback. I also believe that this won't catch modification to existing attributes as opposed to assignments: eg. if one of the attributes is a list and I append to it, this system won't notice. Is that something I can rectify easily? Any other comments or suggestions? Thanks, -- http://mail.python.org/mailman/listinfo/python-list
Re: USBLock : lock/unlock your computer with a USB key
On 11.04.2013 22:16, Ian Kelly wrote: On Thu, Apr 11, 2013 at 9:23 AM, Ethan Furman wrote: On 04/11/2013 04:13 AM, Sven wrote: Yes, I had the idea to add bluetooth too, removes the whole plugging and unplugging spiel. I might start work on that, and if anyone else wants to dive in and help, feel free. I will probably need to refactor the Listener a little, or create a USB and BT listener class. Doesn't BlueTooth have a 30 foot range? For locking I'd rather be at 10 or even 5 feet away. Pair it with a Google Glass and have it lock after you've stopped looking at the screen for 30 seconds. Maybe not with Google Glass, but with a web cam placed on top of the screen. Like Samsung does since the Galaxy S III. There it just happens the other way round: no lock as long as you have your face in front of the phone. bg, Johannes -- GLOBE Development GmbH Königsberger Strasse 260 48157 MünsterGLOBE Development GmbH Königsberger Strasse 260 48157 Münster 0251/5205 390 -- http://mail.python.org/mailman/listinfo/python-list
Add header at top with email.message
Hi, the EmailMessage class of email.message provides the methods add_header() and __setitem__() to add a header to a message. add_header() effectively calls __setitem__(), which does `self._headers.append(self.policy.header_store_parse(name, val))`. This inserts the header at the bottom. It is, however, sometimes desired to insert a new header at the top of an (existing) message. This API doesn’t directly allow this. In my opinion, add_header() should have a flag at_top=False or similar, so that one can get this behaviour (it’ll be a bit difficult with __setitem__). What do you think about this? Is there a feasible way to do this and change the library? Should I post it somewhere where the devs can hear it and suggest that? Thanks, --qsx -- https://mail.python.org/mailman/listinfo/python-list
Re: Add header at top with email.message
Jason Friedman writes:
> I suppose you already figured out that you can call __delitem__() to
> clear the headers and add them back in whatever order you like.
Well, this would mean saving all headers, deleting all, inserting my
own, and adding the saved original headers again. Seems complicated.
> I'm interested in learning more about your use case. Do you have a
> third party with fixed logic that requires the headers in a particular
> order?
Yes, RFC 5321, section 4.4[0] :)
> When an SMTP server receives a message for delivery or further
> processing, it MUST insert trace ("time stamp" or "Received")
> information at the beginning of the message content, as discussed in
> Section 4.1.1.4.
To trace the path a message went, those headers do need to be in a
particular order, or else they won’t make any sense.
[0]: https://tools.ietf.org/html/rfc5321#section-4.4
--
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Re: 1 Million users.. I can't Scale!!
I would need to get a better picture of your app. I use a package called twisted to handle large scale computing on multicore, and multi-computer problems http://twistedmatrix.com/ Hope this is useful, Mike yoda wrote: > Hi guys, > My situation is as follows: > > 1)I've developed a service that generates content for a mobile service. > 2)The content is sent through an SMS gateway (currently we only send > text messages). > 3)I've got a million users (and climbing). > 4)The users need to get the data a minimum of 5 seconds after it's > generated. (not considering any bottlenecks external to my code). > 5)Generating the content takes 1 second. > > I'm considering moving to stackless python so that I can make use of > continuations so that I can open a massive number of connections to the > gateway and pump the messages out to each user simultaneously.(I'm > thinking of 1 connection per user). > > My questions therefore are: > 1)Should I switch to stackless python or should I carry out experiments > with mutlithreading the application? > 2)What architectural suggestions can you give me? > 3)Has anyone encountered such a situation before? How did you deal with > it? > 4)Lastly, and probably most controversial: Is python the right language > for this? I really don't want to switch to Lisp, Icon or Erlang as yet. > > I really need help because my application currently can't scale. Some > user's end up getting their data 30 seconds after generation(best case) > and up to 5 minutes after content generation. This is simply > unacceptable. The subscribers deserve much better service if my > startup is to survive in the market. > -- http://mail.python.org/mailman/listinfo/python-list
What python idioms for private, protected and public?
I have been following this thread with great interest. I have been coding in C++ since the late 80's and Java since the late 90's. I do use private in these languages, with accessors to get at internal data. This has become an ingrained idiom for me. When I create a python object, it is natural for me to want to use familiar idioms. Hare are the places where private is useful to me: Design Intent: 1) mark an object as dirty in a setter (anytime the object is changed, the dirty flag is set without requiring a user to set the dirty flag 2) enforce value constraints (even if just during debugging) 3) lazy init, don't bring the data in until needed 4) adding debug info 5) more here I do write code that violates private - memory ptr access in C++ - reflection in java - aspects in java I usually violate private when adding an aspect to a class, and I don't want this code in every class. Example, persistence. I really like the C# properties, you can access data with a data accessor, but add functionality is triggered when accessing the data. I like the data access syntax, better then the set/get functions. I need the functionality to achieve the design goals above, so i use function, but the are ugly, especially in math code. It would be easy for me to say "Add public and private to python so I can code the way that I am used to". What are some python alternatives to achieve the design intents specified above above? Thanks Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: What python idioms for private, protected and public?
Frederik, Thank you very much for the info on properties, that is very useful. Sorry about the public typo, that should have been protected. I should not post before coffee hits :-) Happy coding, Mike Fredrik Lundh wrote: > Michael Schneider wrote: > > >>1) mark an object as dirty in a setter (anytime the object is changed, >>the dirty flag is set without requiring a user to set the dirty flag > > > properties. > > >>2) enforce value constraints (even if just during debugging) > > > properties. (when you no longer need to enforce things, switch back > to a plain attribute). > > >>3) lazy init, don't bring the data in until needed > > > properties. > > >>4) adding debug info > > > properties. > > >>5) more here > > > properties. > > >>It would be easy for me to say "Add public and private to python so I >>can code the way that I am used to". > > > huh? what do "private" and "public" have to do with what you're describing? > > >>What are some python alternatives to achieve the design intents specified >>above above? > > > properties. > > http://users.rcn.com/python/download/Descriptor.htm#properties > > > > > -- http://mail.python.org/mailman/listinfo/python-list
Re: So far
Take a look at: http://wingware.com/ It is only $35.00 for an IDE. (30 day free eval version) I use eclipse for java, and have become quite fond of tab completion. Mike CppNewB wrote: > I am absolutely loving my experience with Python. Even vs. Ruby, the syntax > feels very clean with an emphasis on simplification. > > My only complaint is that there doesn't appear to be a great commercial IDE > for the language. I've tried Komodo, etc and they are nice applications, > but they don't feel like they give me the "power" like a Visual Studio or > Delphi (I wish I could articulate better the differences).Finding a > descent GUI builder has been a challenge as well. Most of them have support > for Dialogs, but what about more complex UI's? I may need a resizable frame > within a resizable frame? I haven''t found a GUI builder with a great feel > yet. > > Other than that, my experience has been wonderful. Even after my > complaints, I plan on sticking with Python for a while. > > -- http://mail.python.org/mailman/listinfo/python-list
Problems with properties
Hello All,
I have been working on learning how to use python properties.
The get property access is working, but the the set
property is not working.
Rather then dispatching the property assignment to setNothing, the
property object is being replaced with a string.
I must be doing something very stupid here.
Could someone please point out my error, I have dents in my forehead
for this one.
Thanks,
Mike
--
from unittest import TestCase
import unittest
class Task:
def __init__(self,command):
self._command = command
def setNothing(self, value):
raise AttributeError
def getCommand(self):
return self._command
command=property(getCommand, setNothing)
class taskTest(TestCase):
def testTask(self):
t = Task("dir c:")
c = t.command
self.assertEquals("dir c:", c)
# should fail, but doesn't
t.command = "foo Bar"
self.assertEquals("dir c:", t.command)
if __name__ == "__main__":
unittest.main()
--
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Re: Problems with properties
Thanks to all, I added the object as a subclass (should this be
required for 2.4.1 ???)
I also switched to the decorator with the @property syntax
Thank you very much for the help for adding @property to the language.
what a great language :-)
Mike
Michael Schneider wrote:
> Hello All,
>
> I have been working on learning how to use python properties.
>
> The get property access is working, but the the set
> property is not working.
>
> Rather then dispatching the property assignment to setNothing, the
> property object is being replaced with a string.
>
> I must be doing something very stupid here.
>
> Could someone please point out my error, I have dents in my forehead
> for this one.
>
> Thanks,
> Mike
>
>
>
> --
>
> from unittest import TestCase
> import unittest
>
>
> class Task:
> def __init__(self,command):
> self._command = command
>
> def setNothing(self, value):
> raise AttributeError
>
> def getCommand(self):
> return self._command
>
> command=property(getCommand, setNothing)
>
>
> class taskTest(TestCase):
>
> def testTask(self):
> t = Task("dir c:")
> c = t.command
> self.assertEquals("dir c:", c)
>
> # should fail, but doesn't
> t.command = "foo Bar"
>
> self.assertEquals("dir c:", t.command)
>
>
>
> if __name__ == "__main__":
> unittest.main()
--
The greatest performance improvement occurs on the transition of from
the non-working state to the working state.
--
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Re: Problems with properties
Thanks to all, I added the object as a subclass (should this be
required for 2.4.1 ???)
I also switched to the decorator with the @property syntax
Thank you very much for the help for adding @property to the language.
what a great language :-)
Mike
Michael Schneider wrote:
> Hello All,
>
> I have been working on learning how to use python properties.
>
> The get property access is working, but the the set
> property is not working.
>
> Rather then dispatching the property assignment to setNothing, the
> property object is being replaced with a string.
>
> I must be doing something very stupid here.
>
> Could someone please point out my error, I have dents in my forehead
> for this one.
>
> Thanks,
> Mike
>
>
>
> --
>
> from unittest import TestCase
> import unittest
>
>
> class Task:
> def __init__(self,command):
> self._command = command
>
> def setNothing(self, value):
> raise AttributeError
>
> def getCommand(self):
> return self._command
>
> command=property(getCommand, setNothing)
>
>
> class taskTest(TestCase):
>
> def testTask(self):
> t = Task("dir c:")
> c = t.command
> self.assertEquals("dir c:", c)
>
> # should fail, but doesn't
> t.command = "foo Bar"
>
> self.assertEquals("dir c:", t.command)
>
>
>
> if __name__ == "__main__":
> unittest.main()
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Re: Read/Write from/to a process
Jas,
I use a python called twisted to run processes as you describe.
Twisted is an event-driven framework that brings a change in the
way that you look at things.
take a look at:
http://twistedmatrix.com/projects/core/documentation/howto/process.html
Good luck, hope this is useful,
Mike
jas wrote:
> Hi,
> I would like to start a new process and be able to read/write from/to
> it. I have tried things like...
>
> import subprocess as sp
> p = sp.Popen("cmd.exe", stdout=sp.PIPE)
> p.stdin.write("hostname\n")
>
> however, it doesn't seem to work. I think the cmd.exe is catching it.
>
> I also tried
> f = open("out.txt", "w")
> sys.stdout = f
> os.system("cmd.exe")
>
> ..but out.txt didn't contain any output from cmd.exe
>
> So, how can I create a process (in this case, cmd.exe) on Windows and
> be able to read/write from/to it?
>
> Thanks
>
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weakrefs to functions for observer pattern
Hello All,
I am comming back to python after being away for several years.
I would like to use weak refs in an observer pattern implementation.
The problme that I have seems to be that weakrefs can't manage functions.
--- from docs:
http://www.python.org/doc/current/lib/module-weakref.html
Not all objects can be weakly referenced; those objects which can
include class instances, functions written in Python (but not in C),
methods (both bound and unbound), sets, frozensets, file objects,
generators, type objects, DBcursor objects from the bsddb module,
sockets, arrays, deques, and regular expression pattern objects. Changed
in version 2.4: Added support for files, sockets, arrays, and patterns.
---
Is there a technique that I can use to leverage weak references to I
don't have to unregister my observers?
Thanks
Mike
PS. here is the code that I have been working with (Note: I commendout
out the weak ref creation.
import types
class Observable(object):
def addObserver(self, observer, events=None):
if not hasattr(self, '_observers'):
#self._observers = weakref.WeakKeyDictionary()
self._observers = {}
if observer is None:
return
if events is not None and type(events) not in (types.TupleType,
types.ListType):
events = (events,)
self._observers[observer] = events
def removeObserver(self, callable):
if not hasattr(self, '_observers'):
return
if self._observers.has_key(callable):
del self._observers[callable]
##
# Notify all currently-registered Observers.
#
# This observer will be called if the event is one that the
# Observer is interested in, or if event is 'None'
#
# @param event The event to notify the Observers about. None
# means no specific event.
#
# *args - standard arguments - passed through to observer
# **kw - keyword arguments - passed through to observer
def notifyObservers(self, event=None, *args, **kw):
if not hasattr(self, '_observers'):
return
for cb, events in self._observers.items():
if events is None or event is None or event in events:
if cb is not None:
cb(self, event, *args, **kw)
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Re: weakrefs to functions for observer pattern
Alex Martelli wrote: > Michael Schneider <[EMAIL PROTECTED]> wrote: > > >>I would like to use weak refs in an observer pattern implementation. >>The problme that I have seems to be that weakrefs can't manage functions. > > > They can manage just fine functions written in *Python*, just not > "builtin functions*, i.e., ones written in *C*. Just wrap any builtin > function you need to register as observer into a tiny Python-coded > wrapper and live happily ever after. >... > >>Not all objects can be weakly referenced; those objects which can >>include class instances, functions written in Python (but not in C), > > > > Alex Alex, Thank you, I mis-read the docs. The mistake I made was having was using a weak reference as a key in the dictionary. Weak references will be very useful for me. I really enjoy python. So many good things have been added to the language without taking the fun away :-) Mike -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: Using Which Version of Linux
I have been away from unix/linux for a couple of years. I went with SUSE. Just do an install all, and 10 gig later you are done. Very simple install, very easy admin with YAST. If you are a power admin, there may be better release. But if you want simple, but powerful, SUSE has worked well for me. Good Luck, Mike [EMAIL PROTECTED] wrote: > ok, i m going to use Linux for my Python Programs, mainly because i > need to see what will these fork() and exec() do. So, can anyone tell > me which flavour of linux i should use, some say that Debian is more > programmer friendly, or shold i use fedora, or Solaris. Because these > three are the only ones i know of that are popular and free. -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: AJAX => APAX? Or: is there support for python in browsers?
Alex, Good point. Can python be used to write firefox extensions that could be called from javascript? 1) javascript would come in on the HTML page 2) javascript would communication with the Extension API 3) the extension would be written in python That way, you would only need to make your extension's API safe to the wild. It would require the user to download an extension, but flash, et all seem to do ok. Is this possible today? Thanks Mike PS. Sorry for my ignorance on this, I am a client-side developer, trying to explore serious client development. Alex Martelli wrote: > Tim Roberts <[EMAIL PROTECTED]> wrote: >... > >>Internet Explorer will allow any registered ActiveScript language to be >>used in a web page. Python qualifies. In the latest Win32 extensions, >>there is a script in win32comext/axscript/client/pyscript.py that will >>register Python as an ActiveScript language. >> >>The you can say >> >> >> print "Hello, there.
" >> > > > Out of curiosity, how "sandboxed" is this Python? I remember a similar > solution being withdrawn once because it wasn't really safely sandboxed, > so the ``script'' could easily do any arbitrary damage to the machine... > > > Alex -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for small, impressive 3D-related Python script
Ken, I would suggest that you embed python in your app (very easy to do). -And convert several of your existing scripts to python. -Show them a stack of python books for customer training purposes - Drive excel with python (allows integration of your product with other products. - Pick an area of functionality that your product offers today that your customer would like to customize. - convert this alg to python - hack you product to execute the python script - code a variant of the alg in python - execute your variant to demonstrate that python can lower custom development cost, and provide points of extensibility Have fun, good luck, Mike Kenneth McDonald wrote: > I'm not trying to persuade my company to offer Python as a scripting > language for their product, but I am trying to give them examples of > things that Python can do easily that cannot be done easily with their > current proprietary scripting language. After that it would be their > decision. As the product is a 3D package, I'm looking for something in > this field. > > This does _not_ have to use PyOpenGL, or for that matter, any Python 3D > package. In fact, my ideal would be a Python script that simply uses > L-Systems (Lindenmayer systems) as in "The Algorithmic Beauty of > Plants", to generate plantlike OBJ files that can then be displayed in > our program. In general, something that generates an OBJ file would > probably be preferable to something that actually uses PyOpenGL, > Blender, etc, as then I can just display the OBJ file in our program to > say, "This is the sort of thing that can be easily done by Python > without recourse to any other programs". > > So please, any suggestions are welcome. > > As always, many thanks to this group, > Ken -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: Dao Language v.0.9.6-beta is release!
[EMAIL PROTECTED] wrote: ,, However there is one thing I don't like in python, > that is, scoping by indentation. But it would not annoy me so much that > make me decide to implement a new language^_^. > > > Regards, > > Limin > I find these comments interesting. It is very common for people to complain about indentation. I have helped several very large companies create C++ coding standards. One common requirement is very fixed indentation rules. These rules are often encoded into lint-like tools. These tools treat indentation errors like compile time errors. These are often the same people that don't want to use python because it uses indentation .. It is humorous if stand back and look from a distance greater then 10 feet :-) Mike -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to ping in Python?
I telnet to port 13 (returns time) Hope this is helpful, Mike Nico Grubert wrote: > Hi there, > > I could not find any "ping" Class or Handler in python (2.3.5) to ping a > machine. > I just need to "ping" a machine to see if its answering. What's the best > way to do it? > > Kind regards, > Nico -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to ping in Python?
Les, I only ping internal machines. You are right about shutting down ports. When we disable telent, we also disable ping. Many people may not though, good luck, Mike Laszlo Zsolt Nagy wrote: > Michael Schneider wrote: > >> I telnet to port 13 (returns time) >> > The problem is that most modern up-to-date servers use firewalls. They > only open the ports that are absolutely necessary. Usually the time > service is part of inetd, which is disabled by default, on most of the > servers. PING ICMP may work, but sometimes it does not either. In the > worst case, all port are closed and you have no way to tell if there > is a computer or not. > > Can you tell more about what kind of server do you need to "ping"? > > Example: if you need to know if a web server is alive, you should > connect to port 80 (http). If the connection was successful, you can > close the connection immeditelly. You can expect a HTTP server to open > the HTTP port, but all other ports may be closed. > > Les > > > > -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: Ant (with Python extensions) good replacement for distutils?
I would vote against ant because java must be installed to run it. The bootstrap install should be very simple. If you make python usage dependent on: 1) download java 2) install java 3) add java to path 4) download ant 5) install ant 6) add ant to path 7) download ptyhon 8) install python 9) add python to path 10) download package 11) run ant to install package just food for thought, Mike [EMAIL PROTECTED] wrote: > I know distutils well but don't know anything about Ant except that it > is a build > tool from Apache project. > > Could it possible be better or as good as distutils? > (There are extensions for Python.) > > Chris > -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Python OGL Shader Programming
Just curious, is anyone using python for OGL 2.0 shader language development? Which lib are you using? Thanks, Mike -- http://mail.python.org/mailman/listinfo/python-list
Differences between obj.attribute and getattr(obj, "attribute")
Hi list, can somebody explain me the difference between accessing attributes via obj.attribute and getattr(obj, "attribute")? Is there a special reason or advantage when using getattr? bg, Johannes -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: Differences between obj.attribute and getattr(obj, "attribute")
thank you guys.
On 11.12.2013 10:36, Chris Angelico wrote:
2013/12/11 Johannes Schneider :
can somebody explain me the difference between accessing attributes via
obj.attribute and getattr(obj, "attribute")?
Is there a special reason or advantage when using getattr?
You use getattr when the attribute name comes from a string, rather
than a literal. There's no advantage to it when you know ahead of time
what attribute you're looking for. It's useful when you iterate over
dir(), for instance:
print("You can call...")
n=0
for attr in dir(x):
if callable(getattr(x,attr)):
print("x.%s()"%attr)
n+=1
print("...",n," options.")
ChrisA
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Re: Brython (Python in the browser)
On 27.12.2013 07:14, Pierre Quentel wrote: Hi, Ever wanted to use Python instead of Javascript for web client programming ? Take a look at Brython, an implementation of Python 3 in the browser, with an interface with DOM elements and events Its use is very simple : - load the Javascript library brython.js :
Imports in Python
Hi List, I remember some document explaining the python imports in detail somewhere, but I don't have any idea where it was. Even no idea if it was in the List or some blogbost. Does anybody of you have some suggestions where I can find those informations besides the official documentation? bg, Johannes -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: matlabFunction Equivalent?
On 20.01.2014 23:09, rpi.bal...@gmail.com wrote:
Hey all,
I'm new at Python, so if you see any mistakes feel free to let me know.
I'm trying to take a symbolic expression and turn it into a variable equation
or function. I think that just an expression of variables would be preferable.
I have a range equation which I form using symbols and then take various
derivatives of it. I then want to have these derivatives on hand to use for
various functions, but short of using sub every time or just copy pasting from
the console output (I don't want to do that), I can't find an efficient way to
do this. Matlab had matlabFunction which was really handy, but I don't think
Python has an equivalent.
import numpy as np
import scipy as sp
import sympy as sy
import math as ma
x, y, z, x_s, y_s, z_s, theta, theta_dot, x_dot, y_dot, z_dot = sy.symbols('x y
z x_s y_s z_s theta theta_dot x_dot y_dot z_dot')
rho = (x**2 + y**2 + z**2 + x_s**2 + y_s**2 + z_s**2 - 2*(x*x_s +
y*y_s)*sy.cos(theta) + 2*(x*y_s - y*x_s)*sy.sin(theta) - 2*z*z_s)**(0.5)
rho_dot = (x*x_dot + y*y_dot + z*z_dot - (x_dot*x_s + y_dot*y_s)*sy.cos(theta)
+ theta_dot*(x*x_s + y*y_s)*sy.sin(theta) + (x_dot*y_s -
y_dot*x_s)*sy.sin(theta) + theta_dot*(x*y_s - y*x_s)*sy.cos(theta) -
z_dot*z_s)/rho
drho_dx = sy.diff(rho, x)
drho_dy = sy.diff(rho, y)
drho_dz = sy.diff(rho, z)
#I then want drho_dx, etc to be variable expressions with x, y, z, etc as
variables instead of symbols or numbers. I could do:
x, y, z = 1200, 1300, 1400 #m
drho_dx = subs([x, x], [y, y], [z, z])
#but this seems inefficient to do multiple times. Thoughts?
If you don not mind installing other programs, maybe you can have a
look at sage (www.sagemath.org). That's a ComputerAlgebraSystem using
python as its base and supporting most (all?) of the python syntax and
moduls
bg,
Johannes
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Re: SIngleton from __defaults__
On 22.01.2014 20:18, Ned Batchelder wrote: On 1/22/14 11:37 AM, Asaf Las wrote: Chris is right here, too: modules are themselves singletons, no matter how many times you import them, they are only executed once, and the same module object is provided for each import. I'm not sure, if this is the whole truth. think about this example: cat bla.py a = 10 cat foo.py from bla import a def stuff(): return a cat bar.py from foo import stuff print stuff() a = 5 print stuff() from bla import * print a python bar.py 10 10 10 here the a is coming from bla and is known in the global namespace. But the value differs in stuff() and before/after the import statement. So the instance of the module differs -> it cannot be a singelton. bg, Johannes -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: SIngleton from __defaults__
thnx guys. On 24.01.2014 01:10, Terry Reedy wrote: Johannes Schneider Wrote in message: On 22.01.2014 20:18, Ned Batchelder wrote: On 1/22/14 11:37 AM, Asaf Las wrote: Chris is right here, too: modules are themselves singletons, no matter how many times you import them, they are only executed once, and the same module object is provided for each import. I'm not sure, if this is the whole truth. think about this example: cat bla.py a = 10 cat foo.py from bla import a This makes a a global in foo, bound to 10 def stuff(): return a This a refers to the global a in foo. cat bar.py from foo import stuff print stuff() a = 5 This bar.a is irrelevant to the behavior of stuff. print stuff() from bla import * print a python bar.py 10 foo.a == 10 10 foo.a == 10 10 bla.a == 10 here the a is coming from bla Twice and is known in the global namespace. There is no global namespace outside of modules. the value differs in stuff() No it does not. and before/after the import statement. foo.a does not change. bar.a is never used. So the instance of the module differs Nope. Each of the three module instances is constant. The bindings within each could change, but there are no rebinding in the code above. -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: SSH/Telnet program to Router/switch
On 19.02.2014 09:14, Sujith S wrote: Hi, I am new to programming and python. I am looking for a python script to do ssh/telnet to a network equipment ? I know tcl/perl does this using expect/send. Do we have expect available in python as well or need to use some other method ? Regards Sujith I'm using paramiko to access some routers and firewalls from python and it works very well. bg, Johannes -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: The sum of numbers in a line from a file
s = 4
e = 7
with f = file('path_to_file) as fp:
for line in f:
if line.startswith(name):
avg = sum(map(int, filter(ambda x : len(x) > 0,
s.split(' '))[s : e])) / (e - s)
On 20.02.2014 17:22, kxjakkk wrote:
Let's say I have a sample file like this:
Name1 2 34 5 6 78
name1099-66-7871 A-FY10067815998
name2999-88-7766 A-FN99 100969190
name3000-00-0110AUD5100281976
name4398-72-P/FY7684496978
name5909-37-3689A-FY97941006179
For name1, I want to add together columns 4, 5, 6, and get an average from
that, then do the same for the last two columns. I want to do this for every
name.
All I've got is
sum([int(s.strip()) for s in open('file').readlines()])
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Re: why i have the output of [None, None, None]
because thats the return value of [...]
print retuns None.
On 10.04.2014 15:54, length power wrote:
>>> x=['','x1','x2','x3',' ']
>>> x
['', 'x1', 'x2', 'x3', ' ']
>>> [print("ok") for it in x if it.strip() !=""]
ok
ok
ok
[None, None, None]
i understand there are three 'ok' in the output,but why i have the
output of [None, None, None]
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Re: The “does Python have variables?” debate
On 08.05.2014 02:35, Ben Finney wrote: Marko Rauhamaa writes: [..] Python, on the other hand, has this behaviour:: foo = [1, 2, 3] bar = foo # ‘bar’ binds to the value ‘[1, 2, 3]’ assert foo == bar # succeeds foo[1] = "spam"# ‘foo’ *and* ‘bar’ now == [1, "spam", 3] [..] IMHO this is the behavior of having a variable pointing to it's value; foo to the list and bar to foo. consider the following: >>> def f(l): ... l[1] = 'foo' ... >>> l1 = [1,2,3] >>> f(l1) >>> l1 [1, 'foo', 3] this means, l1 consists of "pointers" to its values. Otherwise, it's not calling by reference, because >>> g(l1) >>> l1 [1, 'foo', 3] does not change l1. Once again, if I pass an object it behaves like calling by reference: >>> class A: ... a = 0 ... >>> a = A() >>> a.a 0 >>> def h(a1): ... a1.a = 1 ... >>> h(a) >>> a.a 1 bg, Johannes -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
Re: The possibility integration in Python without an equation, just an array-like file
If you do not have a closed form for T(E) you cannot calculate the exact
value of I(V).
Anyway. Assuming T is integrable you can approximate I(V).
1. Way to do:
interpolate T(E) by a polynomial P and integrate P. For this you need
the equation (coefficients and exponents) of P. Integrating is easy
after that.
2. other way:
Use Stair-functions: you can approximate the Value of IV() by the sum
over T(E_i) * (E_{i+1} - E_i) s.t. E_0 = E_F-\frac{eV}{2} and E_n =
E_F+\frac{eV}{2}.
3 one more way:
use a computer algebra system like sage.
bg,
Johannes
On 16.05.2014 10:49, Enlong Liu wrote:
Dear All,
I have a question about the integration with Python. The equation is as
below:
and I want to get values of I with respect of V. E_F is known. But for
T(E), I don't have explicit equation, but a .dat file containing
two columns, the first is E, and the second is T(E). It is also in the
attachment for reference. So is it possible to do integration in Python?
Thanks a lot for your help!
Best regards,
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Galileo Press GmbH
Rheinwerkallee 4 - 53227 Bonn - Germany
Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax)
http://www.galileo-press.de/
Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker
HRB 8363 Amtsgericht Bonn
--
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Re: What happens when you 'break' a generator?
On 29.07.2014 09:18, Frank Millman wrote: there's not print 'done' statement at the and. Here I break the loop - x = test() for j in x: print(j) if j == 2: break Now the output is - start 0 1 2 'done' does not appear, so the generator does not actually terminate. What happens to it? My guess is that normal scoping rules apply. Using my example, the generator is referenced by 'x', so when 'x' goes out of scope, the generator is garbage collected, even though it never completed. Is this correct? Frank Millman -- Johannes Schneider Webentwicklung johannes.schnei...@galileo-press.de Tel.: +49.228.42150.xxx Galileo Press GmbH Rheinwerkallee 4 - 53227 Bonn - Germany Tel.: +49.228.42.150.0 (Zentrale) .77 (Fax) http://www.galileo-press.de/ Geschäftsführer: Tomas Wehren, Ralf Kaulisch, Rainer Kaltenecker HRB 8363 Amtsgericht Bonn -- https://mail.python.org/mailman/listinfo/python-list
shutil.copyfile is incomplete (truncated)
Using Python 2.7.2 on OSX, I have created a file in temp space, then use the function "shutil.copyfile(fn,loc+fname)" from "fn" to "loc+fname". At the destination location, the file is truncated. About 10% of the file is lost. Original file is unchanged. I added calls to "statinfo" immediately after the copy, and all looks ok (correct file size). filecmp.cmp(fn,loc+fname) print "Statinfo:"+fn+":\n", os.stat(fn) print "Statinfo:"+loc+fname+":\n", os.stat(loc+fname) But when I look at the file in Finder, destination is smaller and even looking at the file (with text editor) file is truncated. What could be causing this? -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
Thanks. Yes, there is a close function call before the copy is launched. No other writes. Does Python wait for file close command to complete before proceeding? -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
> The close method is defined and flushing and closing a file, so > > it should not return until that's done. > > > > What command are you using to create the temp file? > > re command to write the file: f=open(fn,'w') ... then create HTML text in a string f.write(html) f.close -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
> I would consider the chance that the disk may be faulty, or the file > > system is corrupt. Does the problem go away if you write to a different > > file system or a different disk? > It's a relatively new MacBook Pro with a solid state disk. I've not noticed any other disk problems. I did a "repair permissions" (for what it's worth). Maybe I'll have it tested at the Genius Bar. I don't have the full system on another computer to try that; but will work on that today. -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
> > > Or that the filesystem may be full? Of course, that's usually obvious > > > more widely when it happens... > > > > > > Question: is the size of the incomplete file a round number? (Like > > > a multiple of a decent sized power of 2>) > > > > Also on what OS X file system type does the file being created reside, > > in particular, is it a network file system? > File system not full (2/3 of disk is free) Source (correct one) is 47,970 bytes. Target after copy of 45,056 bytes. I've tried changing what gets written to change the file size. It is usually this sort of difference. The file system is Mac OS Extended Journaled (default as out of the box). -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
> The file system is Mac OS Extended Journaled (default as out of the box). I ran a repair disk .. .while it found and fixed what it called "minor" problems, it did something. However, the repair did not fix the problem. I just ran the program again and the source is 47,970 bytes and target after copy if 45,056. Interestingly, the test I run just after the copy , i run a file compare: code: if showproperties: print "Filecompare :",filecmp.cmp(fn,loc+fname) print "Statinfo:"+fn+":\n", os.stat(fn) print "Statinfo:"+loc+fname+":\n", os.stat(loc+fname) results: Filecompare : True Statinfo:/var/folders/p_/n5lktj2n0r938_46jyqb52g4gn/T/speakers.htm: posix.stat_result(st_mode=33188, st_ino=32205850, st_dev=16777218L, st_nlink=1, st_uid=501, st_gid=20, st_size=45056, st_atime=1365749178, st_mtime=1365749178, st_ctime=1365749178) Statinfo:/Users/rmschne/Documents/ScottishOilClub/SOC Board Doc Sharing Folder/Meetings/speakers.htm: posix.stat_result(st_mode=33188, st_ino=32144179, st_dev=16777218L, st_nlink=1, st_uid=501, st_gid=20, st_size=45056, st_atime=1365749178, st_mtime=1365749178, st_ctime=1365749178) It shows file size 45,056 on both source and target, which is the file size of the flawed target, and is not what Finder shows for source. Sigh. -- http://mail.python.org/mailman/listinfo/python-list
Re: shutil.copyfile is incomplete (truncated)
On Friday, 12 April 2013 09:26:21 UTC+1, Cameron Simpson wrote:
>
> | > > Question: is the size of the incomplete file a round number? (Like
>
> | > > a multiple of a decent sized power of 2>)
>
> [...]
>
> | Source (correct one) is 47,970 bytes. Target after copy of 45,056
>
> | bytes. I've tried changing what gets written to change the file
>
> | size. It is usually this sort of difference.
>
>
>
> 45046 is exactly 11 * 4096. I'd say your I/O is using 4KB blocks,
>
> and the last partial block (to make it up to 47970) didn't get
>
> written (at the OS level).
>
>
>
> Earlier you wrote:
>
> | I have created a file in temp space, then use the function
>
> | "shutil.copyfile(fn,loc+fname)" from "fn" to "loc+fname".
>
> and:
>
> | Yes, there is a close function call before the copy is launched. No other
> writes.
>
> | Does Python wait for file close command to complete before proceeding?
>
>
>
> Please show us the exact code used to make the temp file.
>
>
>
> I would guess the temp file has not been closed (or flushed) before
>
> the call to copyfile.
>
>
>
> If you're copying data to a tempfile, it will only have complete
>
> buffers (i.e. multiples of 4096 bytes) in it until the final flush
>
> or close.
>
>
>
> So I'm imagining something like:
>
>
>
> tfp = open(tempfilename, "w")
>
> ... lots of tfp.write() ...
>
> shutil.copyfile(tempfilename, newfilename)
>
>
>
> Note above no flush or close of tfp. So the final incomplete I/O
>
> buffer is still in Python's memory; it hasn't been actually written
>
> to the temp file because the buffer has not been filled, and the file
>
> has not been closed.
>
>
>
> Anyway, can you show us the relevant bits of code involved?
>
>
>
> Cheers,
>
> --
>
> Cameron Simpson
>
>
>
> Processes are like potatoes.- NCR device driver manual
Thanks for the observation.
Code (simplified but results in same flaw) (which a close, far as I can tell).
def CreateSpeakerList1():
import shutil
import filecmp
import os.path
t=get_template('speaker_list.html')
fn=TEMP_DIR+SOC_SPEAKER_LIST
fn=tempfile.gettempdir()+"/"+SOC_SPEAKER_LIST
f=open(fn,'w')
speaker_list=Speaker.objects.order_by('status__order','targetmtg__date')
print "Creating " + SOC_SPEAKER_LIST + " ..."
html=(smart_str(t.render(Context(
{
'css_include_file':CSS_INCLUDE_FILE,
'css_link':False,
'title': ORG_NAME+" Speaker List",
'speaker_list': speaker_list,
}
f.write(html)
f.close
print "Wrote "+fn
shutil.copyfile(fn,SOC_GENERAL_OUTPUT_FOLDER+SOC_SPEAKER_LIST)
print "Filecompare
:",filecmp.cmp(fn,SOC_GENERAL_OUTPUT_FOLDER+SOC_SPEAKER_LIST)
print "Statinfo:"+fn+":\n", os.stat(fn)
print "Statinfo:"+SOC_GENERAL_OUTPUT_FOLDER+SOC_SPEAKER_LIST+"\n",
os.stat(SOC_GENERAL_OUTPUT_FOLDER+SOC_SPEAKER_LIST)
return
Output on latest run:
Creating speakers.htm ...
Wrote /var/folders/p_/n5lktj2n0r938_46jyqb52g4gn/T/speakers.htm
Filecompare : True
Statinfo:/var/folders/p_/n5lktj2n0r938_46jyqb52g4gn/T/speakers.htm:
posix.stat_result(st_mode=33188, st_ino=32332374, st_dev=16777218L, st_nlink=1,
st_uid=501, st_gid=20, st_size=45056, st_atime=1365758139, st_mtime=1365758139,
st_ctime=1365758139)
Statinfo:/Users/rmschne/Documents/ScottishOilClub/Output/speakers.htm
posix.stat_result(st_mode=33188, st_ino=32143886, st_dev=16777218L, st_nlink=1,
st_uid=501, st_gid=20, st_size=45056, st_atime=1365758029, st_mtime=1365758139,
st_ctime=1365758139)
--
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Re: shutil.copyfile is incomplete (truncated)
On Friday, 12 April 2013 10:22:21 UTC+1, Chris Angelico wrote: > On Fri, Apr 12, 2013 at 7:18 PM, Rob Schneider wrote: > > > f.close > > > > Yep, there's the problem! See my previous post for details. Change this to: > > > > f.close() > > > > and you should be sorted. > > > > ChrisA Slapping forehead ... hard. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: - E04 - Leadership! Google, Guido van Rossum, PSF
Congratulations to Guide, Mike Harald Armin Massa wrote: > Guido at Google: a message in THE public forum c.l.p. > > A confirmation by Martellibot, that Guido is IN FACT sitting 15m > distant from him; and everybody in Python knows where Martellibot has > his desk. > > Can it get more official than this? > > yeah: > a confirmation by Greg Stein @ Google within slashdot, that Guido is > working at Google. > > I am sure that more people in the Python community are reading c.l.p. > and /. than the washington post, the people affected have been > informed. > > I guess that's as formal and official as it can get. > > And concerning Guido, Python, community and leadership: > > Guido is the designer, the creator of Python. He has nearly unlimeted > trust in his design decisions: we all know, that he is THE gifted > language designer. His proclamations are accepted because he has proven > over time that he knows what's best for the language. > > Allow me to quote Greg Stein: > "Ha! Guido would quit in a heartbeat if you tried to make him manage > people. That just isn't where he's at. He's absolutely brilliant and > loves to write excellent code. Great. We're gonna let him do just that > :-)" > > So, Google with their geek-version of the Playboy-Mansion, free massage > parleurs, free lunch and dinner and best recruitment tactics on the > planet and the known universe will not be able to make Guido manage > people. > > Somehow the Python community managed itself through the years... Python > grew healthy and steadily; forked less then usual, inspired other > languages and got faster and faster and faster. > > Maybe only mediocre and less ideas need a great leader. Maybe a great > idea can lead for itself? > > Harald > > -- > GHUM Harald Massa > persuadere et programmare > Harald Armin Massa > Reinsburgstraße 202b > 70197 Stuttgart > 0173/9409607 > -- The greatest performance improvement occurs on the transition of from the non-working state to the working state. -- http://mail.python.org/mailman/listinfo/python-list
Re: Writing pins to the RS232
Jay,
Couple of points that may help you.
1) A serial port does not have data ports 0-n. A serial port takes a
byte (8 bits), then shifts them down a single pipe using a chip called a
UART (feel free to google for unfamiliar terms).
example
Bit pattern 1010 1010
would be shifted one bit at a time
1
0
1
0
1
0
1
0
a one is +5 volts on single send line of the UART and 0 is 0 volts.
RS232 uses a different mapping for 1's and 0's (but is still serial)
1 - ~-3V - -12 V
0 0-12 V
So you slap a chip on between the UART and the RS232 pin (usually a
MAX232) that translates the voltages for you.
On the other end of the wire
232 socket
MAC232
UART (usually built into the microcontroller)
Register in Microcontroller
I like playing at this level. I would recommend using AVR
microcontroller (easiest to program and there is an open source
gcc compiler).
for $20.00 US you can buy the butterfly eval board with:
- microcontroller
- max232 all wired up for rs232 connection from your computer
- lcd display
- temperature sensor
- light sensor
- the avr mega169 has many goodies
- analog - digital converter
- digital -> analog converter
- LCD controller
This is a great bargin.
If you are starting out in microcontrollers. I would suggest that you
go to:
http://smileymicros.com/
They sell a nice package for $90.00
- butterfly eval board
- great, easy to follow book on how to develop on microcontrollers for
the beginer.
- project kit - includes everything you need to build all of the
projects (even includes the wire ;-)
There are python libs that support Ateml Avr connections:
It is easy to use your rs232 serial with a microcontroller at the other
end of the wire. Microcontrollers are cheap. If you fry why is
connected to your devices, you are only out the microcontroller.
Have fun,
Mike
[EMAIL PROTECTED] wrote:
> I want to write to the pins of an RS232 without using the serial
> protocol. The use would be every pin could act to complete a circuit
> in customized hardware. I could use python to communicate serially to
> a BASIC stamp or a Javelin stamp and then use the stamp to set however
> many pins as 0's or 1's but should it be that hard to do with python.
> I've looked through how python does serial with the "serial" module but
> it just uses Java's javax.comm libraries. Is there anyway to do very
> low level device writing to COM ports?
>
> In summary I'm looking for something like:
> ser = serial.Serial(0)
> ser.pin0 = 1
> ser.pin1 = 1
> ser.pin2 = 1
>
>
>
> or
> ser.write('0xFF')
> which would set 8 pins on the RS232 cable to 1's
>
--
The greatest performance improvement occurs on the transition of from
the non-working state to the working state.
--
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Weird gcc errors while installing "MySQL-python" module
Hi guys, I´m experiencing weird error messages while installing MySQL-python with easy_install... I have no idea where the errors come from. Read the whole output at http://pastebin.com/m3859cf40 It´s really a lot... Someone got ideas? Greets Jonas -- http://mail.python.org/mailman/listinfo/python-list
Re: Choosing a new language
Rico Secada <[EMAIL PROTECTED]> wrote: > > Second, I need some advice. > http://www.nondot.org/sabre/Mirrored/AdvProgLangDesign/ Learn, or better said understand, those and then choose wisely. Lisp throws lambda calculus right into your face, which is a good thing. Scheme might be the better choice, it's lexically scoped: http://mitpress.mit.edu/sicp/ There are also video lectures with people with funny hats speaking wise words. For lisp, (and also a good read if you go for scheme, same with the wizard book above the different way round), the book of choice is http://www.paulgraham.com/acl.html Python is Yet Another Scripting Language, borrowing concepts from more advanced languages. You might want to go for the real thing instead, although it's certainly nice. Haskell is to scheme what a basketball basket is to a trash bin. It's typed strictly and pure, but with some effort you will also be able to throw your trash through the basket as well as find a trash bin big enough for your ball . -- (c) this sig last receiving data processing entity. Inspect headers for past copyright information. All rights reserved. Unauthorised copying, hiring, renting, public performance and/or broadcasting of this signature prohibited. -- http://mail.python.org/mailman/listinfo/python-list
Re: Choosing a new language
Tim Roberts <[EMAIL PROTECTED]> wrote: > Xah Lee <[EMAIL PROTECTED]> wrote: > > > >Let me tell you, since you know PHP, that PHP and Perl are > >practically identical in their high-levelness or expressiveness or > >field of application (and syntax), and, Perl and Python are pretty > >much the same except their syntax. > > I agree with the fundamental sentiment here, but it's important to > note that the syntax difference between Perl and Python is an enormous > consideration. > > The biggest problem with Perl's syntax, in my view, is that it is > darned near impossible to write Perl code that can be read and > understood later, by anyone, including the author. I've used both > languages extensively, and even with all of that experience, it takes > considerable effort for me to go back to the Perl scripts I wrote 4 > or 5 years ago and grasp what they actually do. > > With Python, on the other hand, much of the source code reads like > English prose. It's certainly possible to code "write-only" > sequences by abusing comprehensions and generators, but obfuscations > like that are the exception rather than the rule. Should I start a flame war? Shouldn't I? It's New Year's Eve, after all, fits quite nicely. Perl excels on executing braindumps. Python is quite good in that area, too. Haskell, too, but only if you think Haskell. And Haskell has style. Good style. Very good style, to be exact. In the end that means that you can't read your Perl and Python programs 'cos your brain was a bit muddy at the time you wrote it. Well, with Haskell this would never happen, as you wouldn't have ever been able to write such atrocious code in the first place. You would rather think about the problem in detail, get disabused by old aunty typecheck, abstract, and write completely unintelligent code _after_ understanding that your brainmuddiness was actually complete clarity, it was the language you were trying to implement it in that made it muddy. And now please all stop posting and let me get completely drunk in relative peace. -- (c) this sig last receiving data processing entity. Inspect headers for past copyright information. All rights reserved. Unauthorised copying, hiring, renting, public performance and/or broadcasting of this signature prohibited. -- http://mail.python.org/mailman/listinfo/python-list
Using python22.dll with Python 2.5?
Hi! I'd like to use the numpy library (which runs on Python 2.5) in the same project with another (mandatory) library which needs python22.dll. When I try to compile I get an error similar to "python22.dll not compatible with the current Python version." Has anybody an idea how to solve this? Thanks for your ideas. Best regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Two-dimensional array tutorial?
Hi! I'd like to handle two-dimensional arrays. My first choice, the numpy library, doesn't seem to be an option due to compatibility issues (see my other thread about python22.dll). Is there a tutorial somewhere how to handle 2d-arrays with vanilla Python? Thanks and best regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Two-dimensional array tutorial?
Diez B. Roggisch schrieb: Can't you just get Numpy (or it's predecessors, Numeric) compiled against ptyhon2.2? I tried Numeric, but e.g. it doesn't seem to feature transpose... How do I compile Numpy against python2.2? :-) Thanks for your answers and best regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Two-dimensional array tutorial?
Robert Kern schrieb: Martin Schneider wrote: I tried Numeric, but e.g. it doesn't seem to feature transpose... Yes, it does. Numeric.transpose() Then I must have made a mistake. I'll look into it. Thanks for the correction. How do I compile Numpy against python2.2? :-) You cannot. The first version of numpy required Python >= 2.3. Yeah, I read in your other post, which crossed mine. Sh*t :-) Thanks and best regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: concatenate the elements in each list of a list of lists
Am Wed, 23 Jul 2008 08:33:57 -0700 wrote antar2: > I already asked a similar question, but encounter problems with > python... > How can I concatenate the elements in each list of a list of lists > > list_of_listsA = > > [['klas*', '*', '*'], > ['mooi*', '*', '*', '*'], > ['arm*', '*', '*(haar)']] > > wanted result: > > list_of_listsA = > > [['klas* * *'] > ['mooi* * * *'] > ['arm* * *(haar)']] > > Thanks a lot ! Hello, maybe this will help: In [5]: list_of_listsA = [['klas*', '*', '*'], ['mooi*', '*', '*', '*'], ['arm*', '*', '*(haar)']] In [6]: s = "" In [7]: print [[s.join(item)] for item in list_of_listsA] [['klas***'], ['mooi'], ['arm***(haar)']] regards Michael -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter: The good, the bad, and the ugly!
rantingrick schrieb: On Dec 29, 6:41 pm, Gerry Reno wrote: wxPython looks good but I don't see anyone developing support for things like smartphones. No wx is not the answer to our problems Rather: ... to *your* problem... Also, what do you think about frameworks such as pyjamas? It lets you write in python and compiles everything down to Javascript so it can be used across the Web as well as on the desktop. Hmm, this is like two double edged swords smashing one another in battle. Sword One: On one hand web frameworks are going to be really big soon -- however legacy GUI's are not going away any time soon! There are enough out there in the wild, they will last quite for awhile indeed; but it's time for them to die. Sword Two: On the other hand web frameworks provide awesome cross platform ability that is surly only going to get better as time goes -- however i utterly hate JavaScript (although much worse web languages exist!). And sending requests back and forth between Python, JavaScript, Apparently the authors do know that, too: MessageID:, *sigh* no svg. BTW: Look in comp.lang.javascript: javascript is framework/toolkit resistent. and BrowserX is also a real PITA. Because even though everyone knows this is coming all the major browsers are trying to insert their API into the mix. So that Joe Scripter has to write code that is compatible between many browsers. Until the world agrees on a unified API --AND IMPLEMENTS IT SERIOUSLY-- we are at the mercy of drunken sailors at the helm. svg: opera, chrome, safari(including ios), ie9, firefox. Although svg is missing under webkit/android --Apple kept the hardware accelerated part to themeselves. Goolge is currently implementing hardware acceleration for svg in chrome/webkit, likewise Microsoft/ie. Lets wait and see when svg becomes available in android, too. Although smil is quiet another subject. I believe pyjamas has a bright future in the web playground, however we still need to focus our community efforts towards a Python based GUI. I can see a pythonGUI and pyjamas existing side by side in mutual harmony for many years. pyjamas: Perhaps without javascript. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: [OT] Python like lanugages
Tim Harig schrieb: [snip] This isn't such a tragedy Erlang as it is for other managed VMs because Erlang/BEAM makes powerful usage of its VM for fault tolerance mechanisms. I don't know of any other VM that allows software upgrades on a running system. styx, the distributed operating system inferno, language: limbo. -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter: The good, the bad, and the ugly!
Terry Reedy schrieb: On 1/16/2011 11:20 PM, rantingrick wrote: Ok, try this... http://juicereceiver.sourceforge.net/screenshots/index.php http://www.sensi.org/~ak/pyslsk/pyslsk6.png http://www.wxwidgets.org/about/screensh.htm Ok, wxwidgets can look at least as good as tk. Agreed that wxpython might instead link to the excellent wxwidgets page. Well, tosssing screenshots around doesn't prove wether a framwork/toolkit is good or not; It only displays the developers commitment to create a work of art. Lets examine one of your examples: http://juicereceiver.sourceforge.net/screenshots/index.php#mac Overall impression: The software was designed for windows; more or less following the windows hci-guidelines, The windows version is resonable good. About the Aqua screenshots: 1. Negative actions are located on the falling diagonale. 2-3. The select background and foreground inside the multi-column listbox have the wrong color--the used color originates from text fields. 4. The multi-column listbox should have vertical gridlines. 5-6. Too much top and bottom padding inside the column header. 7. The column texture is wrong --there is a visible line in the bottom. 8. There are white boxess around the input fields. 9. Header column label and lisstbox content are not aligned. 10. There is separator line between the status bar and the brusshed dialog. 11. Last picture: there is a single page inside the tabet control. 12. Last picture: The text "Select radio ..." is trucated, the dialog isn't large enough. 13. The Scheduler activation should come before customizing the scheduler. 14. The dialog uses sunken group boxes for some sections, these group should be 2% darker than their surrounding container. 15. The spacing rules from the aqua hci guidlines are violated. The inner tabset should have 20px distance from both sides, 20px from the bottom, 14px from top. 16. Second last picture: The button lables are truncated. 17. Tree: Uses the wrong folder symbols--from windows--, select background and foreground are wrong, too. - The Aqua hci-guidlines discourage group boxes, the same with the windows guidlines, too. Get rid off group boxes. - second last picture: There should be more top padding for the checkbutton inside the white rectangle; best the same as left-padding. - There no focus frames visilbe inside these screenshots, it would be interessting to see how those are realised. - The icon buttons should be brushed, likewise shoud the column header have brushed background. - Aqua hci guidelines: All dialogs should have a centered appearance. Back to rantingrick 21st century toolkit/framwork: Let's have a look at the numbers: Worlwide pc market are 300 Million pcs per year, this number includes desktops(2/3) and servers(1/3). Your gui app is not relevant on servers. Quite a good deal of the remaining pc's are sold in countries with rampant ilict software copies; Since there are no software cost for these copies the people tend to install the big, bloated software pieces from named computer companies --you wont sell linux there, because it is more expensive than an ilict windows+office++. ~ 100 Million potential new desktop users for you. Apple's projection for the ipad in 2011 are 65 Million pieces, iphone and ipod touch will be roughly the same. 130 Million ios pieces. ~ 130 Million new ios users for you. The android market is still unclear, but I do suppose it will rival ios, lets say 100 Million in 2011. ~ 100 Million new android users for you. Microsoft mobile and blueberry are wildcards; no serious forecast is possible for these devices. Lets assume: ~ 50 Million blueberry, windows mobile. Total is: 380 Million potential new user for your application. wxWidgets: 3600 LOC, python: 140 LOC --these are very old numbers, but from the same time period. wxWidgets on desktop, present for windows, Aqua and X11. wxWidgets on ios, possible but unlikely, the thing is way to big for any ios device. wxWidgets on android not realistic. wxWidgets on blueberry not possible. wxWidgets on windows mobile; development is silverlight with .net, so wxWidgets would have to be ported to .net; not realistic. python on desktop, present. python on ios, possible --if not yet present. python on android, present. python on blueberry, possible. python on windows mobile, present--but .net support deprecated by ms. The smartphone and table market has only started, yet. In 2011 the mobile market is already larger than the desktop pc, almost 3 times largerv. The desktop pc market is in decline; there is however a shift toward pc-servers, instead. It is anybodies guess how far the pc-desktop decline will go. Every 21st century toolkit or framework must run on mobile platforms! wxWidgets was written ~1992, it is a copy of mfc, which in turn is a copy of MacApp. MacApp is also OSS, maintained through an industrie consortium. Why do yo
Re: Tkinter: The good, the bad, and the ugly!
Octavian Rasnita schrieb: From: "Arndt Roger Schneider" At least keep the disclaimer: >> Well, tosssing screenshots around doesn't prove wether >> a framwork/toolkit is good or not; >> It only displays the developers commitment to create >> a work of art. Overall impression: The software was designed for windows; more or less following the windows hci-guidelines, The windows version is resonable good. This is the most important thing, because most users use Windows. Those who have other preferences are not forced to choose Windows, so it's their choice, and if the interface doesn't look so nice, that's it. See disclaimer. Since you mentioned "nice": I do not use such words to charcterize a gui. I think the developers of said software tried hard to make it "nice" and "beauty", hence the brushed background and group-boxes --BTW: the windows Guidelines also discourage using group-boxes for usability reasons (see Theo. Mandel object oriented user interfaces). Back to rantingrick 21st century toolkit/framwork: Let's have a look at the numbers: Worlwide pc market are 300 Million pcs per year, this number includes desktops(2/3) and servers(1/3). Your gui app is not relevant on servers. Quite a good deal of the remaining pc's are sold in countries with rampant ilict software copies; Since there are no software cost for these copies Python is an open source software and the programmers that use Python might also prefer to offer open source software for free so this is not important. And "not legal" is not a very correct term, because somebody from Iran or North Corea must respect the laws from his/her country and in her/his country some things might not be forbidden by law, so it may be perfectly legal. Nice cropping, >>the people tend to install the big, bloated software >pieces from named computer companies >>--you wont sell linux there, because it is more >> expensive than an ilict windows+office++. Illict as in unlicensed. Law has nothing to do with it. And yes these unlicensed sofware has an negative impact on the distribution of free open source software. I wonder, what license do you use in your own work, and what do you think about people which violate your license? ~ 100 Million potential new desktop users for you. Apple's projection for the ipad in 2011 are 65 Million pieces, iphone and ipod touch will be roughly the same. 130 Million ios pieces. The android market is still unclear, but I do suppose it will rival ios, lets say 100 Million in 2011. ~ 100 Million new android users for you. Microsoft mobile and blueberry are wildcards; no serious forecast is possible for these devices. Lets assume: ~ 50 Million blueberry, windows mobile. Total is: 380 Million potential new user for your application. wxWidgets: 3600 LOC, python: 140 LOC --these are very old numbers, but from the same time period. This is a bad comparison because the programs targetted to the mobile phones are in most cases very different than the programs that need to be used on the desktop. This is the marketplace for all gui applications, and not a comparision. Do you want to say that WxPython is not good just because it doesn't work well on mobile phones? I do not comment on the quality of either wxWidgets nor wxPython. Both exist for certain reasons. The desktop pc was the sole target for all the big C++ gui class liraries in 1992. Over time a large code base evolved which makes it very difficult to get these class libraries into new markets--such as today with mobile devices. Those numbers show that only the mobile phones are important, because there are more mobile phones than computers. No, it doesn't. There are billions of mobile phones with graphical user interfaces, still these phones weren't relevant for gui applications. Well, Python needs a better GUI lib for using them on desktop computers, not on mobile phones. wxWidgets is suiteable for the desktop. The desktop pc market is in decline; there is however a shift toward pc-servers, instead. What do you mean by declining? Are there fewer desktop PCs today than a year ago? I am writing about graphical applications not computers. Looking into wxWidgets: Interactivity: keyboard focus, shortcuts, function keys, active foreground, active background are obsolete. hovering tooltips obsolete, status bar to large, obsolete. scrolled dialogs, obsolete. OK, Cancel, Retry, Abort buttons, obsolete, file dialogs obsolete, old style printing obsolete, drag-and-drop obsolete... Who says that they are obsolete? A good GUI interface should offer keyboard accessibility. Otherwise it is broken. OK, I take keyboard focus back. Summary wxWidgets: wxWidgets is large scale C++ library from the 20th century, solemnly dedicated toward desktop computers.
Re: Tkinter: The good, the bad, and the ugly!
rantingrick schrieb: On Jan 18, 7:09 am, Arndt Roger Schneider wrote: Summary wxWidgets: wxWidgets is large scale C++ library from the 20th century, solemnly dedicated toward desktop computers. wxWidgets originates from a time before templates were used in C++ and thus duplicates many of today's C++ features. wxWidgets is not suitable for a modern type GUI ad thus clearly not the toolkit/framework of the 21st century. Alight i'll except that Rodger. Wx may be unusable for the mobile market. And since the mobile market is exploding --and will continue to explode-- then we need to consider this. However, does any GUI library exist that can handle desktop, mobile, and accessibility and do it all in a 21st century way? You slaughtered wx but failed to provide any alternative, however i am listing to your advice contently because it is very good advice. Read on... Thanks! Again this is not about the quality of wxWidgets, wxWidgets grew large because there was vested interest in it. Its success is its undoing. We DO need to consider the mobile market in this decision. Maybe it is time for us to actually get on the cutting edge of GUI's. Maybe we should head an effort to create a REAL 21st century GUI that can handle desktop, mobile, and accessibility, and do it all whilst looking very sharp! Sure we rob from peter to pay paul. We will use Tkinters awesome API and geometry managers, wxPythons feature richness, and any other code we can steal to make this work! I am not sure whether this sarcasms or for real..., so I'll take for genuine. Tk is also doomed, and Tkinter isn't Tk. You are right about keeping the separate geometry managers, though. For starters: http://kenai.com/projects/swank Swank publishes java/swing classes as tk in jtcl, which is similar to what tkinter does for python and tk. It should be feasible to use swank with the tkinter interface for jpython--without jtcl. However, this doesn't make tkinter mobile, neither is swing available on android. When you look into the android developer documents concerning the gui, then you can see that the gui model is quite similar to tk. So I suppose android can be reached by jpython in a two stage process. The other devices are more difficult to reach, though. There is webkit on some, but not all. Webkit is available for the desktop, ios and android--today without svg. There are two ways to gain graphical independence: First a basic implementation for each platform and second through abstraction. With abstraction I mean to base the gui on a common graphical model present on all platforms and hence to implement the "toolkit" on-top of it in python (not C, C++, java,javascript), python! The single common graphical model is SVG. Then we can "advertise" python as the best GUI language available. I have nothing against seeing Python on more devices and this would no doubt bring that dream into fruition. There is a huge hole in the market at this very moment and we need to pounce on it like a hungry tiger on wildebeest. Just think how wonderful it would be to switch from mobile to desktop and still write beatiful Python code. So be it. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter: The good, the bad, and the ugly!
rantingrick schrieb: On Jan 18, 12:25 pm, Arndt Roger Schneider wrote: rantingrick schrieb: On Jan 18, 7:09 am, Arndt Roger Schneider We DO need to consider the mobile market in this decision. Maybe it is time for us to actually get on the cutting edge of GUI's. Maybe we should head an effort to create a REAL 21st century GUI that can handle desktop, mobile, and accessibility, and do it all whilst looking very sharp! Sure we rob from peter to pay paul. We will use Tkinters awesome API and geometry managers, wxPythons feature richness, and any other code we can steal to make this work! I am not sure whether this sarcasms or for real..., so I'll take for genuine. No this is real, albeit a bit fantastical. Thats probably why you thought it was sarcasm :). However, we need to start a revolution in the GUI world. Currently we (as developers) are slaves to the OEM's and OS's. This must change. We must unify GUI coding the same way OpenGL unified graphics coding. Multiplicity is ruining any and all advancements in Graphical User Interfaces. Sure multiplicity is great in emerging systems (language, culture, GUI, etc, etc) However at some point you must reign in this multiplicity and harness the collective knowledge into an all encompassing standard. OpenGUI is that standard. It should be shipped with every OS in the world. This is the only way we can have mobile, desktop, and accessibility all combined into one beautiful package. Then the contest come down to who can create the best abstraction API. There has been no advancement in GUI-Design. Today it looks and behaves just the way Bill Atkinson designed it. Technical revolutions are made by disruptive thoughts, which are never collective. ...The problem with gui-design:It requires an graphical artist, a well versed writer, a software architect and a programmer. The first two job description are the important ones. ...No OS-vender is going to allow that, it equals lost control. Tk is also doomed, and Tkinter isn't Tk. You are right about keeping the separate geometry managers, though. For starters:http://kenai.com/projects/swank This looks like a very young project (beta) and i could not find a widget set. However i will investigate more. Thanks alpha However we need to think beyond even a Python community scale. This problem is inherent in every language community out there. We to unify the GUI standard. And we are a decade behind in development. (yes i am completely serious about all of this!). Then we did find common ground. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter: The good, the bad, and the ugly!
Adam Skutt schrieb: On Jan 18, 8:09 am, Arndt Roger Schneider wrote: Back to rantingrick 21st century toolkit/framwork: Let's have a look at the numbers: Worlwide pc market are 300 Million pcs per year, this number includes desktops(2/3) and servers(1/3). Your gui app is not relevant on servers. You should tell this "fact" to just about every major enterprise software manufacturer out there. They all ship GUI tools intended to be used on the server. Some of them ship only GUI tools or CLI tools that are worthless, making you use the GUI tools. The desktop pc market is in decline; there is however a shift toward pc-servers, instead. It is anybodies guess how far the pc-desktop decline will go. Every 21st century toolkit or framework must run on mobile platforms! Until we have pixel-perfect touch sensors, toolkits for devices with pointer interfaces (e.g., PCs) and toolkits for devices with touch interfaces (e.g., phones and tablets) will necessarily be different. You note this yourself: the UI paradigms that work well when you have a pixel-perfect pointer do not work at all when you have a touch screen, especially on a limited size and resolution display. Yes I did and that's how it is. Even if you're provided a "single" toolkit, you still end up with two, maybe three, different applications, each using different widgets targeted for the device they run on. And no one provides a "single" toolkit: while Silverlight can run on the desktop, the web, and now on Windows Phone, you can't use the same widgets everywhere; ditto with Cocoa for OS X and Cocoa Touch for iTouch devices. While some further unification is obviously possible, it's rather doubtful we'll ever have unified widgets that are truly workable on the web, on the "desktop", and on a portable touch screen device. Think about all the programmers earning their butter and bread :-). Forget toolkits and widgets for awhile. What remains are specific types of human/computer interactions, a visual representation on a screen and a predefined behaviour for said human action. E.g. a button is: A function gets asychnronously performed in response to a finger/mouse click and release inside a certain screen area. --A widget is essentially a logical abstraction. wxWidgets was written ~1992, it is a copy of mfc, which in turn is a copy of MacApp. MacApp is also OSS, maintained through an industrie consortium. Why do you not use the original framework? Because it's not cross-platform, I'd imagine. The entire point of wxWidgets was to provide a cross-platform "OOP" UI toolkit. It closely copies MFC since MFC and XView were the two "backends" it supported. MacApp is/was cross-platform, Apple pulled the plug on the non-mac platforms; the industrie consortium took charge of the other platforms. Screen resolution: The time of 72ppi CRT monitors is over. A GUI framework/toolkit must be resolution independent, including all icons and indicators; it should use decluttering (newspeak:ZUI). WPF is the only functional resolution-independent UI toolkit in existence. While I don't disagree with you in principal, practice is pretty heavily divorced from principal here. Principal doesn't help me write GUI applications today. wxWidgets is not suitable for a modern type GUI ad thus clearly not the toolkit/framework of the 21st century. None of the toolkits accessible from CPython are suitable for a 21st century guy by your standard. If we talk about IronPython, Silverlight becomes the closest, but it isn't a panacea by any stretch of the imagination. Adam According to Microsoft neither is silverlight. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Screen readers for Tkinter (was Re: Tkinter: The good, the bad, and the ugly!
Littlefield, Tyler schrieb: >And of course, it should also offer support for Windows, since most of the computer users use Windows, especially those who need accessibility features. uh. no, and no. Plenty of those utilizing screen readers are using macs nowadays, as well as vinux or some derivitave there of. Do you have first hand experience with it under AQUA? I think Tk-aqua (also 8.6) should work out-of-the-box with brail-lines, text-to-speech and such; the older carbon built however wont... -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: [Code Challenge] WxPython versus Tkinter.
rantingrick schrieb: [snip] 1. You cannot define the terms--restrict your opponent-- and battle it yourselves. 2. Your specified directory browser is useless. --At least define that the directory browser must have constant complexity to work with volatile data over a network... -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with giant font sizes in tkinter
Steven D'Aprano schrieb: On Thu, 10 Feb 2011 15:48:47 +, Cousin Stanley wrote: Steven D'Aprano wrote: I have a tkinter application under Python 2.6 which is shows text in a giant font, about twenty(?) times larger than expected. The fonts are set using: titlefont = '-Adobe-Helvetica-Bold-R-Normal-*-180-*' buttonfont = '-Adobe-Helvetica-Bold-R-Normal-*-140-*' labelfont = '-Adobe-Helvetica-Bold-R-Normal-*-140-*' Although I've been a linux user for several years, that type of font spec hurts my head :-) Will the more simplistic type of tuple spec not work in your tkinter application ? I don't know, but I'll give it a try. Nevertheless, I'd like to learn how to diagnose these sorts of font issues. Can anyone suggest where I should start? Those adobe helveticas are bitmap fonts. Tk 8.5 uses freetype to render fonts under X11, if you wish to use outdated bitmap fonts under X11, then disable-xft when building Tk 8.5. I do assume there are different tk versions on your various platforms, and the troubling one is with version 8.5 --8.5 uses anti-aliasing hence freetype. Recommendation: Get rid of bitmap fonts under X11. BTW the default fonts under Linux are: bitstream vera sans (for helvetica) bitstream vera (for times) and bitstream vera sans mono (for courier). In my opion those bitstream fonts are much better than the mentioned Adobe fonts. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Displaying SVG in tkinter using cairo and rsvg
Martin P. Hellwig schrieb: Hi all, Information on using tkinter for displaying an svg image seems a bit low spread on the Internet. I recently played around with pygame and svg and realized, hold on this can be done with tk too. So I thought I post a little example for future generations :-) (and also have stored at http://dcuktec.googlecode.com/hg/source/examples/cairo_rsvg_tkinter.py). So here it is if you are interested: [snip] raster images from SVG: There are multiple methods to convert a scalable vector graphic into a bitmap. In addition to cairo, librsvg and rsvg imageMagick contains a vector graphic format similar to svg--gradients and transparency are problematic for this approach, but its a while since I had looked into it... My product Jeszra imports svg into Tk(using tkpath http://jeszra.sourceforge.net/jeszra/Jeszra_TechnicalNotes.html#d0e10279 ), preserving it as a vector graphics. There are, of course, limitations to what can be preserved in Tk: http://jeszra.sourceforge.net/jeszra/SVG_Import.html The other way is much simpler to convert a Tk graphics into svg, which is also implemented in Jeszra. All svg graphics on http://jeszra.sourceforge.net and http://gestaltitems.sourceforge.net are generated by Jeszra from Tk (there are some hundred graphics)... The generator API is open and a draft documentation is online at: http://jeszra.sourceforge.net/api/ch01s04.html http://jeszra.sourceforge.net/api/index.html Jeszra API Concerning svg: http://jeszra.sourceforge.net/api/ch04.html http://jeszra.sourceforge.net/api/ch05.html http://jeszra.sourceforge.net/api/ch06.html http://jeszra.sourceforge.net/api/ch07.html http://jeszra.sourceforge.net/api/ch08.html Here is an overview about Jeszra, SVG and Tk: http://jeszra.sourceforge.net/api/pictures/overview.svg The svg on those page gets on-demand converted into flash, for the internet explorer. Is there anyting else You want to know about svg? -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Displaying SVG in tkinter using cairo and rsvg
Martin P. Hellwig schrieb: On 02/16/11 09:04, Arndt Roger Schneider wrote: [snip] tkpath does not seem to come standard with Python's tk version when I looked into it a couple of years ago, but maybe it has now? tk canvas and tkpath share the same interface, the first tkpath was a plugin into the tk canvas. A tkinter wrapper class will be a simple subclass of tk canvas introducing the new item types: path, ppolygone, polyline, circle, elipsis, pimage, prect, ptext, group and for tkpath 0.3 three additional messages for: style, gradient and distance, that's all ~50 lines of code. Is there anyting else You want to know about svg? No not really :-), I just wanted to display a SVG in tkinter with the minimal amount of external dependencies, since I have achieved that I thought I share my experience, so that the next time someone google tkinter and display svg it will return something that (well at least of the time of this writing) worked. Well CAIRO is sort of a shifting target... --currently I am stuck with PPC and new CAIRO versions cannot longer being built on it anymore :-(-- CAIRO can be real pain on non-X11-linux platforms. ImageMagick is simpler than CAIRO cross-platform wise. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and Tkinter Programming by John Grayson
Pradeep B schrieb: On Sat, May 29, 2010 at 7:33 PM, Kevin Walzer wrote: Tkinter doesn't wrap native printing API's. There are a few extensions that do it, but they are platform specific and not complete. The usual ways of printing are like this: 1. If you're outputting data from the text widget, write that to a temporary text file and print via lpr. 2. If you're outputting data from the canvas, write that to a temporary postscript file and print via lpr. This is on Unix/MacOS. Not sure what the equivalent API on Windows is. --Kevin -- Kevin Walzer Code by Kevin http://www.codebykevin.com -- http://mail.python.org/mailman/listinfo/python-list Thanx Kevin. Anybody can throw light on how to do the same in Windows ? -pradeep The conventional --crude-- way is to take the bitmap of a window and to stretchDIBBitBlt it onto the printer device in windows and osx. Native printer dialogs do exist for both platforms ... When you do not need a printer dialog: Convert the Tk-GUI to SVG, then wrap it into a fo-xml wrapper --fo accepts inline SVG-- and use fop for printing. This approach works cross-platform, albeit you need a Java intallation (fop is a Java application). You can use http://jeszra.sourceforge.net to generate SVG for a complete Tk-GUI. In addition. there is a python/tkinter SVG export project for the Tk canvas --search the tkinter wiki. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs - A Modest Proposal
Terry Reedy schrieb: Ant I agree that the current tk situation is not completely satisfactory. In particular, the IO facilities are inadequate and have not, to my knowledge, changed in a decade. Image input formats are limited. There is no canvas output as an image. (Output of the canvase display list as a dialect of postscript that not everything can read is not a substitute for this.) Hah, You are ill-informed. tkpath 0.3 contains a surface element, which renders vector graphics elements in an off-screen tk image. Forget postscript! Generate SVG from a tk canvas or --better-- from tkpath. Jeszra (from me) generates SVG. There is also a SVG export package available in python/tkinter, search the tkinter wiki. However... I think it important that Python come with a minimal IDE that is adequate for someone like me doing Python-only development. I thank the programmers of IDLE. So merely deleting tk/tkinter is not an option. Indeed, having something similar to and at least as good as IDLE for any candidate gui replacememt should and I think would be a requirement for consideration. Yes, use emacs or vim, without any GUI. The problem with the big gui application frameworks are that they are too big. The two I have glanced at -- wx... and qt -- have much more than gui stuff and duplicate parts of the Python stdlib and other 3rd party libs. The question is: What sort of devices are being used by *normal* computer owners in the near future? My guess: It wont be a Desktop Computer. Will any big GUI-Framework work on those devises? No! Will a light-weight GUI-toolkit being ported to these devices ? Perhaps, but not likely. Will any scripting language run on such devices? Perhaps, but not likely, if then it will be Ecmascript or a 4GL. Will SVG run on thoses devices? Yes, it must, because SVG is an integral part of OEBPS, and the tiny implementation is already part most mobile phones. Take a look at SVG for BlackBerry for instance. As for a small gui written in Python, you seem to have ignored the link to pygui. Of course that has its own problems. Among others: it is incomplete; it ignore Python 3 (requires 2.3+ should be 2.3 to 2.6), which is the only place it could be added; the api sytle is not standard in Python (get_xx and set_xx methods instead of direct access or properties); and there is nothing yet like IDLE. What would be required is a Python3 GUI project with multiple contributors. Terry Jan Reedy What sort of GUI project? On the initial proposition: Grapical design is art and art requires an artist. A community cannot work like an artist. The best a community of top-class *graphical designers* could produce would be of mediocre quality. -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs - A Modest Proposal
Terry Reedy schrieb: On 6/7/2010 5:25 PM, Arndt Roger Schneider wrote: Terry Reedy schrieb: ... Hah, You are ill-informed. How about 'under-informed'? That I readily admit ;-) tkpath 0.3 contains a surface element, which renders vector graphics elements in an off-screen tk image. As far as I know, tkpath is either not part of the tk that comes with python, or not accessible via tkinter, or not documented. 3x Correct. Tkpath 0.2 is a plugin into tk canvas. Tkpath 0.3 is a standalone replecement for tk canvas. The tkpath interface is identical to tk canvas, but it features additional objects: path, polyline, ppolygon, pline, ptext, circle, ellipse, radial gradients, linear gradients, groups and styles. The original tk canvas elements are the same as with tkpath, but the new elements are the tk counterpart to those elements listed inside the svg 1.1 specification. As for documentation; Use the Jeszra book, the svg 1.1 specification and the ascii text documentation distributed with tkpath. tkpath bypasses the X-emulation layer for the new elements under Windows and OSX. CAIRO is the backend under X11. Forget postscript! Gladly! Generate SVG from a tk canvas or --better-- from tkpath. Jeszra (from me) generates SVG. I found http://jeszra.sourceforge.net/ It looks interesting but not quite what I need, which is to export a tk canvas that I draw on with Python in a form I can import into OpenOffice. OpenOffice does --not yet-- have an svg import filter. You will have to convert SVG into another format. For example: use a fo-wrapper around your SVG and convert this fo-xml into pdf (fop / java). Other options are: inkscape, adobe illustrator, gimp--if you can life with a raster image. I guess SVG import has highest priority within the OpenOffice project --you wont need such workarounds for long. There is also a SVG export package available in python/tkinter, search the tkinter wiki. I presume you mean there is a 3rd party python add-on package that exports from a tk canvas. Can you be more specific as to what you meant? Googling 'tkinter wiki' got me to http://tkinter.unpythonic.net/wiki/ wiki.python.org/moin/TkInter has a link to the same. Searching there for 'svg' title or text has no hits. Searching PyPI also turns up nothing obvious. Googling further, I found canvasvg.py at http://wm.ite.pl/proj/canvas2svg/index.html via an answer to a question at http://bytes.com/topic/python/answers/629332-saving-output-turtle-graphics I will give it a try. Terry Jan Reedy That was it! Be aware only tk canvas elements are exported to SVG by this package. Jeszra on the other hand converts an entire GUI into SVG. I don't have any experience with this python package--for obvious reasons. What you should look after is how raster images are included in the generated SVG; and try each of the 12 different arrow shapes for tk line. If you have controls on your canvas: You may use the screenshot facility of tkImg to create an image from each control, then embed the screenshot base64 encoded inside the generated SVG.- -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: GUIs - A Modest Proposal
rantingrick schrieb:
On Jun 10, 9:38 pm, Stephen Hansen wrote:
Also-- you're just starting to get wrong.
http://docs.python.org/library/tix.html
They don't -call- them the things you are, but between ComboBox, and the
flexibility of HList and TList... it actually offers quite a lot.
Urm, do you *know* what a Grid widget is Stephen? (hint: Excel) Do you
*know* what a ListCtrl is Stephen? (Hint: File Browser in report or
iconlabel views) Neither of those widgets exists in the Tix package.
And how do i *know* this? Well because unlike you i have actually
written code with Tix widgets, obviously you have not.
All this stuff is present in Tk!
OpenGL:
tkzinc, a 2D visualiation system based on OpenGL,
this one is widley used in air-traffic control...
BTW: tkinc features the best transformation system in the
IT--the author got a patent for it.
canvas3d, OpenGL-3D.
In addition there are *very very very large* visualization systems
available in Tk:
vtk for example...
ListCtrl --besides that I truely hate this type of controls, an
aggregation of usablility problems--
tkTreeCtrl is a true clone of MSWIN Explorer
Spreadsheet:
Well, whow doesn't exist in Tix! Are you sure? Hint: look again.
There is tktable, technically well done with on-demand data aquisition,
looks really ugly. An open field to display your artistic prowess.
Once upon a time there was a complete
spreadsheet application written in C++/Tk: abacus.
The TList only displays iconlabels in a wrapping column format, not in
any "report mode" ala: Windows Explorer("details mode"). The HList
widget is for showing a tree structure and is NOTHING like either a
ListCtrl or a Grid.
See above.
But notice this windows explorer type sort of thing is a major offence
on other platforms.
My own approach for such an interface function is to use seperate window
types, it reduces the maintainment cost for such an application.
HList:
Well *now* I am speachless. Did you actually even do a superfical
research on the topic?
BLT-tree
bwidget-tree
rtl_tree
hugelist
tkTreeCtrl (mentioned above)
ttk:treectrl
tablelist
tixtreecontrol
Just scanning the docs of a module (that you know jack about) and then
parroting off some baseless arguments are bound to bite you in the
@ss! *egg on face*
Please enjoy it.
-roger
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Re: GUIs - A Modest Proposal
lkcl schrieb: [snip] it's the exact same thing for SVG image file-format. i'm _definitely_ not convinced that "SVG the image fileformat" is The One True Way to design images - but i'm equally definitely convinced of the power of SVG manipulation libraries which allow for the creation SVG images using declarative programming. You rather severly underestimate the impact from SVG! 1. SVG is a complete visualization system and not an fancy way to create icons. SVG and SMIL are an extreme powerful environment. With it's possible to create(design) sophisticated graphical and interactive --resolution independent-- applictions without resorting to javascript or direct DOM manipulations. Javascript or other languages are still necessary to feed data into an SVG visualization, but not for much more. Further more SVG and the GPU are a natural combination. 2. Many of CSS shiny new features --such as animation originate from SVG. 3. SVG-Print: Printing is one of the biggest problems in the current IT-landscape. I do not want to install printer drivers on each telephon I own, neither on any other device --mobile or not. The printer must contain a computer running an OS and has to handle an agreed upon page description language (Xml based)... Using HTML/CSS/DOM/javascript for application building: Well, yes can be done. HTML is however text oriented; each application entirely based on this technology will be satured with text. HTML works reasonable well with applications of the past two decades, but the importance of text is dwindling and other graphical means of communication become more and more relevant. but, all that having been said, and returning to "HTML and CSS (the fileformats)", there's a lot to be said for convincing people who are stuck in those worlds of the benefits and freedom of declarative programming... _without_ having to get involved directly in javascript. Any User Interface should be pre-determined; this concept allows the consequent separation of application logic and presentation. It's not only important for Web-applications! that web apps are about to take over the world, etc. There is still a place for GUI toolkits that are not based on the DOM, that there definitely are. or whatever the W3C technology of the month is. :) don't underestimate how much time and money is going into the W3C standards! and remember, someone's got to implement them, so the actual proof of the pudding is not what the W3C thinks but whether the technology ends up actually in the hands of users and is successful _for users_. l. The mony part is definitly important. Tk is actually a good example for the working of money-politics (the absence thereof). -roger -- http://mail.python.org/mailman/listinfo/python-list
Re: Customising Tk widgets
Peter schrieb:
I am using Windoze, I suspect the appearance attributes I am asking
about here are platform dependent?
Using Tkinter, I would like to generate a Checkbutton that is filled
in with a solid colour rather than a tick mark when selected.
tk = Tk()
tk.option_add("*Checkbutton.inidcatorOn", 0)
Could somebody provide some pointers as to how I could achieve this?
Also, John Shipman's Tkinter reference shows the Radiobutton drawn as
a diamond and yet when I create one in Windows I get a circle - again,
how and where do I need to look to change this behaviour?
Thanks
Peter
Shipman's screenshots are made under Tk 8.4/X11, featureing the
motif look-a-like.
Tk 8.4 follows the windows user style guide (windows95) under windows.
You could still get the motif look under windows:
Tk 8.5 is bundled with a theming engine ttk, this engine
uses the built-in theming engine under windows xp and later,
but also allows you to supplant this engine.
The related ttk theme is called "classic".
-roger
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