Re: Returning a custom file object (Python 3)
On Thursday 28 May 2015 15:49, Chris Angelico wrote:
> ... but I don't think replacing all of open() is what Steven has in
> mind; it's a function that does a lot of work, most of which is what's
> wanted.
Correct. If I wanted to replace open(), I would have just shadowed it, or
monkey-patched it, or just used myopen().
I want open() to return my own subclass instead of the standard one. And I
think you have the solution I was looking for:
> Depending on how brutal you want to be, though, you _could_ hack around
> it.
>
from io import TextIOWrapper
class MyFile(TextIOWrapper):
> ... def demo(self): print("Hello, world!")
> ...
f = open("/tmp/dummy", "w", encoding="utf-8")
f
> <_io.TextIOWrapper name='/tmp/dummy' mode='w' encoding='utf-8'>
f.__class__
>
f.__class__ = MyFile
f.demo()
> Hello, world!
>
> This does appear to work. Whether or not it's a good idea is a
> separate question.
And this is EXACTLY the sort of use-case that having __class__ be writable
is intended to solve. So this is exactly the solution I was after, thank
you. Er... except for one little problem... in Python 3.3:
py> f = open("/tmp/a", "r")
py> f.__class__ = MyFile
Traceback (most recent call last):
File "", line 1, in
TypeError: __class__ assignment: only for heap types
So it doesn't work for me. What version of Python are you using?
--
Steve
--
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Re: Returning a custom file object (Python 3)
On Thu, May 28, 2015 at 5:04 PM, Steven D'Aprano
wrote:
>> This does appear to work. Whether or not it's a good idea is a
>> separate question.
>
>
> And this is EXACTLY the sort of use-case that having __class__ be writable
> is intended to solve. So this is exactly the solution I was after, thank
> you. Er... except for one little problem... in Python 3.3:
>
> py> f = open("/tmp/a", "r")
> py> f.__class__ = MyFile
> Traceback (most recent call last):
> File "", line 1, in
> TypeError: __class__ assignment: only for heap types
>
>
> So it doesn't work for me. What version of Python are you using?
Huh, didn't even think to check other versions.
$ python3
Python 3.5.0b1+ (default:7255af1a1c50+, May 26 2015, 00:39:06)
[GCC 4.9.2] on linux
It's a build fresh from source control around about this weekend (some
time after feature freeze, obviously, but beyond that all I know is
what you see there). I guess this is pretty new; trying the same thing
on 3.4.2 doesn't work. But hey! 3.5 will be out soon...
ChrisA
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Re: Returning a custom file object (Python 3)
On 28 May 2015 at 03:16, Steven D'Aprano wrote:
> I'd like to return a custom file object, say my own subclass. I can easily
> subclass the file object:
>
>
> from io import TextIOWrapper
> class MyFile(TextIOWrapper):
> pass
>
>
> but how do I tell open() to use MyFile?
Does the below do what you want?
#!/usr/bin/env python3
class Wrapper:
def __init__(self, wrapped):
self._wrapped = wrapped
def __getattr__(self, attrname):
return getattr(self._wrapped, attrname)
# Special methods are not resolved by __getattr__
def __iter__(self):
return self._wrapped.__iter__()
def __enter__(self):
return self._wrapped.__enter__()
def __exit__(self, *args):
return self._wrapped.__exit__(*args)
class WrapFile(Wrapper):
def write(self):
return "Writing..."
f = WrapFile(open('wrap.py'))
print(f.readline())
with f:
print(len(list(f)))
print(f.write())
>
> Answers for Python 3, thanks.
Tested on 3.2.
--
Oscar
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Hi. I have questions about Python
Hi.Please note that do not speak english well. Do you know Python 2 vs Python3 MultiProcessing the difference ?Multiprocessing is better performance? Search results do not make a big difference. Why it will occur following the performance issues ?http://www.reddit.com/r/Python/comments/37khen/is_that_why_python3_slower_than_python2/ Thank you. 블로그서명까뭉이 멜랑꼴리 만원은 구겨져도 천원이 되지 않는다.-- https://mail.python.org/mailman/listinfo/python-list
[QT] Scroll multiple lists with one scrollbar
Hello everyone! My QT GUI contains 8 QlistWidgets filled with a large amount of data. Each item of a list is related to items of other lists in the same row. So I want to scroll the 8 lists with only one vertical scrollbar (and vice-versa) But I don't know how to manage this. Do you have an idea? (I'm quite new in python, I'm translating my tcl/tk app to this code) thanks in advance -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
You want to define a scrollable area and then add your labels to it. The code here: http://stackoverflow.com/questions/22255994/pyqt-adding-widgets-to-scrollarea-during-the-runtime should show you what you need to do, though for you the job is easier if you do not need to add the labels after the app is running. Laura -- https://mail.python.org/mailman/listinfo/python-list
Question About Image Processing in Python
Hello All, I want to know which version of Python is compatible (or can be associated with which version of which "tools or package" for image processing) I am working under Window and it is so complicated to find out which version of which tool goes with which other version? I want to use the following package “numpy, matplotib, mahotas, ipython OpenCV and SciPy" Let say I use Python 2.7 or Python 2.10 which version of the following tools “numpy, matplotib, mahotas, ipython, OpenCV and SciPy” should I use? and where can I find them? Are there any package available for image processing using Python 3.4.3? Or what is the recommendation of Python for image processing? Do you know any good Python book on the subject or tutorial ? Thank you enormously, Christian -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
Le jeudi 28 mai 2015 12:12:42 UTC+2, Laura Creighton a écrit : > You want to define a scrollable area and then add your labels to it. > The code here: > http://stackoverflow.com/questions/22255994/pyqt-adding-widgets-to-scrollarea-during-the-runtime > > should show you what you need to do, though for you the job is easier if you > do not need to add the labels after the app is running. > > Laura Thanks Laura. But as I understand the scrollable area, it's useful to scroll widgets. But here, in my case, I want to scroll inside my widgets. My QlistWidgets are fixed in size and data are append inside. Because I want only one scrollbar for all lists, I set the "setVerticalScrollBarPolicy" lists property to "ScrollBarAlwaysOff" and tried to do what I need with a QScrollBar. -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
In a message of Thu, 28 May 2015 03:44:22 -0700, Alexis Dubois writes: >Le jeudi 28 mai 2015 12:12:42 UTC+2, Laura Creighton a écrit : >> You want to define a scrollable area and then add your labels to it. >> The code here: >> http://stackoverflow.com/questions/22255994/pyqt-adding-widgets-to-scrollarea-during-the-runtime >> >> should show you what you need to do, though for you the job is easier if you >> do not need to add the labels after the app is running. >> >> Laura > >Thanks Laura. >But as I understand the scrollable area, it's useful to scroll widgets. >But here, in my case, I want to scroll inside my widgets. >My QlistWidgets are fixed in size and data are append inside. >Because I want only one scrollbar for all lists, I set the >"setVerticalScrollBarPolicy" lists property to "ScrollBarAlwaysOff" and tried >to do what I need with a QScrollBar. Ah, sorry, I misunderstood the question. Hmmm. I've never tried to do that. Let me see if I can get something to work. Back later, hack hack hack! Laura -- https://mail.python.org/mailman/listinfo/python-list
Re: Question About Image Processing in Python
On 5/28/2015 6:34 AM, Serge Christian Ibala wrote: I want to know which version of Python is compatible (or can be associated with which version of which "tools or package" for image processing) pillow is a one standard for image processing but I see that mahotas does different things. pillow is both 2.x and 3.x. I am working under Window and it is so complicated to find out which version of which tool goes with which other version? The magic site for Windows binaries is http://www.lfd.uci.edu/~gohlke/pythonlibs/ Now pip installable with an extra arg if not automatic. I want to use the following package “numpy, matplotib, mahotas, ipython OpenCV and SciPy" opencv seems to be the only one not available for 3.x. Python 2.7 or Python 2.10 which version of the following tools no 2.10, just 2.7.10, which is what you should install. “numpy, matplotib, mahotas, ipython, OpenCV and SciPy” just try pip install xyz and let it pick but see above if necessary for Windows binaries. Are there any package available for image processing using Python 3.4.3? -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
Re: Question About Image Processing in Python
On 28 May 2015 at 11:34, Serge Christian Ibala wrote: > Hello All, > > I want to know which version of Python is compatible (or can be associated > with which version of which "tools or package" for image processing) > > I am working under Window and it is so complicated to find out which version > of which tool goes with which other version? > > I want to use the following package > > “numpy, matplotib, mahotas, ipython OpenCV and SciPy" I would just install the most recent released versions unless I saw some information that suggested a problem with that. You may want to consider installing something like the Anaconda Python distribution which includes most of these packages (all except mahotas) with a single installer: http://docs.continuum.io/anaconda/install.html You can see the list of packages included here: http://docs.continuum.io/anaconda/pkg-docs.html It will also install the mingw compiler that you could use to install mahotas using pip/conda. -- Oscar -- https://mail.python.org/mailman/listinfo/python-list
Re: Question About Image Processing in Python
On Thu, May 28, 2015 at 1:05 PM, Terry Reedy wrote: > On 5/28/2015 6:34 AM, Serge Christian Ibala wrote: > > > I want to use the following package >> >> “numpy, matplotib, mahotas, ipython OpenCV and SciPy" >> > > opencv seems to be the only one not available for 3.x. > > OpenCV 3 (which is in RC1 now) supports Python 3.x. -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
Looks like what you need to do is to
connect verticalScrollBar().valueChanged (in one widget) to
verticalScrollBar().setValue in all of the others.
So is this code on the right track? It uses lists, not labels, and
doesn't hide the scrollbars, but is this the behaviour you need (
and weren't getting)? It should work for labels too..
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.listA = QtGui.QListWidget(self)
self.listB = QtGui.QListWidget(self)
self.listC = QtGui.QListWidget(self)
widgets=[self.listA, self.listB, self.listC]
layout = QtGui.QHBoxLayout(self)
for w1 in widgets:
layout.addWidget(w1)
for index in range(100):
w1.addItem('This is line number %d' % (index +1))
for w2 in widgets:
if w1 != w2:
w1.verticalScrollBar().valueChanged.connect(w2.verticalScrollBar().setValue)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
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Re: [QT] Scroll multiple lists with one scrollbar
Alexis Dubois wrote: > My QT GUI contains 8 QlistWidgets filled with a large amount of data. > Each item of a list is related to items of other lists in the same row. > So I want to scroll the 8 lists with only one vertical scrollbar (and > vice-versa) > > But I don't know how to manage this. > Do you have an idea? > > (I'm quite new in python, I'm translating my tcl/tk app to this code) > thanks in advance Are you perhaps looking for a table widget? https://srinikom.github.io/pyside-docs/PySide/QtGui/QTableWidget.html -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
Thanks Peter, but no, even if it could be possible to use a QTableWidget instead of my 8 lists. -- https://mail.python.org/mailman/listinfo/python-list
Re: [QT] Scroll multiple lists with one scrollbar
Thank you Laura, it works. (Even if connecting the scrollbar of one list to other lists is not what I exactly want to do, but no matter, I change the line "w1.verticalScrollBar().valueChanged.connect(w2.verticalScrollBar().setValue)" a little bit to fit my need. ) -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
Marko Rauhamaa writes: > Ned Batchelder : > >> I would find it much clearer to not use a nested class at all, and >> instead to pass the object into the constructor: > > Nested classes are excellent and expressing the state pattern http://en.wikipedia.org/wiki/State_pattern>. Do you have an example of state pattern using nested classes and python? With a quick look I didn't happen to find one in any language. -- https://mail.python.org/mailman/listinfo/python-list
Re: Question About Image Processing in Python
Serge Christian Ibala wrote: > Or what is the recommendation of Python for image processing? Basic setup everyone should have: Python NumPy SciPy (e.g. scipy.ndimage) Cython C and C++ compiler matplotlib scikit-image scikit-learn pillow Also consider: mahotas tifffile (by Christoph Gohlke) OpenCV PyOpenGL VTK mayavi pyglet PyGame PyQt Abandonware: PIL -- https://mail.python.org/mailman/listinfo/python-list
Re: Hi. I have questions about Python
이현상 wrote: > Hi.Please note that do not speak english well. > Do you know Python 2 vs Python3 MultiProcessing the difference > ?Multiprocessing is better performance? The main difference is that multiprocessing on Python 3.4 (and later) will allow you to use APIs that are not "forksafe" on Linux or Mac. One example is Accelerate Framework on Mac OSX (e.g. used by numpy.linalg). -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
Anssi Saari :
> Do you have an example of state pattern using nested classes and
> python? With a quick look I didn't happen to find one in any language.
Here's an sampling from my mail server:
class SMTPServerConnection(ServerConnection):
#: : :
#: : :
def __init__(self, server, sock, domain, peer):
super().__init__(server, sock)
conn = self
client_ip = peer[0]
class STATE:
def __str__(self):
return self.__class__.__name__
def handle_command(self, cmd):
conn.log("handle_command (unexpected): {}".format(cmd))
assert False
def handle_bad_command(self, reason):
conn.log("handle_bad_command (unexpected): {}".format(reason))
assert False
def handle_eof(self):
conn.log("eof (unexpected)")
assert False
def terminate(self):
assert False
class IDLE(STATE):
def handle_command(self, cmd):
conn.log("handle_command: {}".format(cmd))
verb, args = conn.split_cmd(cmd)
if verb == b'EHLO':
self.process_ehlo_or_helo(
args,
"PIPELINING",
"SIZE {:d}".format(conn.MAX_MSG_SIZE),
"VRFY",
"EXPN",
"8BITMIME")
elif verb == b'HELO':
self.process_ehlo_or_helo(args)
elif verb in [ b'NOOP', b'RSET' ]:
conn.respond(250, "OK")
elif verb == b'HELP':
conn.respond(214, "No help available")
elif verb in [ b'VRFY', b'EXPN' ]:
conn.respond(550, "Access denied to you")
elif verb == b'QUIT':
conn.respond(221, "{} Closing channel".format(
server.domain))
conn.shut_down()
conn.set_state(QUITTING)
elif verb == b'MAIL':
self.handle_mail(args)
elif verb in [ b'RCPT', b'DATA' ]:
conn.respond(503, "Bad sequence of commands")
else:
conn.respond(500, "Command unrecognized")
def process_ehlo_or_helo(self, args, *capabilities):
if not args:
conn.respond(501, "Missing parameter")
return
try:
# may be an IP address
conn.helo_domain_name = args[0].decode()
except UnicodeError:
conn.respond(501, "Bad encoding in parameter")
return
if conn.local_client:
conn.respond(250, server.domain, *capabilities)
conn.set_state(IDLE)
return
## todo: remove the "suspend" concept from mux
conn.suspend()
conn.log("authorize helo {} from {}".format(
conn.helo_domain_name, client_ip))
conn.set_state(SPF_HELO)
def callback(verdict, reason):
conn.state.handle_spf_verdict(
verdict, reason, *capabilities)
conn.spf_query = server.spf_client.authorize_helo(
server.host, conn.helo_domain_name, server.family,
client_ip, callback, xid = id(conn))
#: : :
#: : :
class SPF_HELO(STATE):
def terminate(self):
conn.resume()
conn.spf_query.cancel()
conn.close()
if conn.timer is not None:
conn.timer.cancel()
conn.timer = None
conn.set_state(ZOMBIE)
def handle_spf_verdict(self, verdict, reason, *capabilities):
conn.resume()
conn.log("verdict {} reason {}".format(verdict, reason))
# RFC 4408 §2.5.5 calls for leniency for SoftFail
#if verdict in [ SPFClient.FAIL, SPFClient.SOFT_FAIL ]:
if verdict in [ SPFClient.FAIL ]:
conn.respond(550, "SPF check failed: {}".format(reason))
conn.set_state(IDLE)
return
conn.respond(250, server.domain, *capabilities)
conn.set_state(IDLE)
class SPF_SENDER(STATE):
def terminate(self):
conn.resume()
conn.spf_query.cancel()
conn.close()
if conn.timer is not None:
conn.timer.cancel()
conn.timer = None
conn.set_state(
Re: [QT] Scroll multiple lists with one scrollbar
In a message of Thu, 28 May 2015 05:53:34 -0700, Alexis Dubois writes: >Thank you Laura, it works. >(Even if connecting the scrollbar of one list to other lists is not what I >exactly want to do, but no matter, I change the line >"w1.verticalScrollBar().valueChanged.connect(w2.verticalScrollBar().setValue)" >a little bit to fit my need. ) Great, I had to go to a meeting, so things were not in such a nice state as I would have liked. In particular, if some of your lists are never going to have any scroll bars attatched to them, there is no need to wire them up to the thing. But I thought I had found the little bit of magic you needed; glad I was correct this time. Laura -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
On Thu, May 28, 2015 at 9:01 AM, Marko Rauhamaa wrote: > Anssi Saari : > >> Do you have an example of state pattern using nested classes and >> python? With a quick look I didn't happen to find one in any language. > > Here's an sampling from my mail server: I think I would be more inclined to use enums. This has the advantages of not creating a new set of state classes for every connection instance and that each state is a singleton instance, allowing things like "if self.state is SMTPConnectionState.IDLE". It could look something like this: class SMTPConnectionState(Enum): class IDLE: @classmethod def handle_command(cls, conn, cmd): # ... class SPF_HELO: @classmethod def terminate(cls, conn): # ... -- https://mail.python.org/mailman/listinfo/python-list
Re: Creating a reliable sandboxed Python environment
Thanks for the responses folks. I will briefly summarize them: > As you say, it is fundamentally not possible to make this work at the Python level. This is pretty effectively demonstrated by "Tav's admirable but failed attempt to sandbox file IO": * http://tav.espians.com/a-challenge-to-break-python-security.html Wow there are some impressive ways to confuse the system. I particularly like overriding str's equality function to defeat mode checking code when opening files. > When we needed this at edX, we wrote CodeJail > (https://github.com/edx/codejail). It's a wrapper around AppArmor to provide OS-level protection of code execution in subprocesses. It has Python-specific features, but because it is based on AppArmor, can sandbox any process, so long as it's configured properly. This looks promising. I will take a closer look. > What about launching the Python process in a Docker container? This may work in combination with other techniques. Certainly faster than spinning up a new VM or snapshot-restoring a fixed VM on a repeated basis. Would need to see whether CPU, Memory, and Disk usage could be constrained at the level of a container. - David On Monday, May 25, 2015 at 7:24:32 PM UTC-7, davi...@gmail.com wrote: > I am writing a web service that accepts Python programs as input, runs the > provided program with some profiling hooks, and returns various information > about the program's runtime behavior. To do this in a safe manner, I need to > be able to create a sandbox that restricts what the submitted Python program > can do on the web server. > > Almost all discussion about Python sandboxes I have seen on the internet > involves selectively blacklisting functionality that gives access to system > resources, such as trying to hide the "open" builtin to restrict access to > file I/O. All such approaches are doomed to fail because you can always find > a way around a blacklist. > > For my particular sandbox, I wish to allow *only* the following kinds of > actions (in a whitelist): > * reading from stdin & writing to stdout; > * reading from files, within a set of whitelisted directories; > * pure Python computation. > > In particular all other operations available through system calls are banned. > This includes, but is not limited to: > * writing to files; > * manipulating network sockets; > * communicating with other processes. > > I believe it is not possible to limit such operations at the Python level. > The best you could do is try replacing all the standard library modules, but > that is again just a blacklist - it won't prevent a determined attacker from > doing things like constructing their own 'code' object and executing it. > > It might be necessary to isolate the Python process at the operating system > level. > * A chroot jail on Linux & OS X can limit access to the filesystem. Again > this is just a blacklist. > * No obvious way to block socket creation. Again this would be just a > blacklist. > * No obvious way to detect unapproved system calls and block them. > > In the limit, I could dynamically spin up a virtual machine and execute the > Python program in the machine. However that's extremely expensive in > computational time. > > Has anyone on this list attempted to sandbox Python programs in a serious > fashion? I'd be interested to hear your approach. > > - David -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
Ian Kelly : > On Thu, May 28, 2015 at 9:01 AM, Marko Rauhamaa wrote: >> Anssi Saari : >> >>> Do you have an example of state pattern using nested classes and >>> python? With a quick look I didn't happen to find one in any >>> language. >> >> Here's an sampling from my mail server: > > I think I would be more inclined to use enums. This has the advantages > of not creating a new set of state classes for every connection > instance and that each state is a singleton instance, allowing things > like "if self.state is SMTPConnectionState.IDLE". It could look > something like this: > > class SMTPConnectionState(Enum): > > class IDLE: > @classmethod > def handle_command(cls, conn, cmd): > # ... > > class SPF_HELO: > @classmethod > def terminate(cls, conn): > # ... Really, the main expressive choice is whether you use an inner class (and get the advantages of a closure) or an outer class (and get potential performance advantages). When I have coded state machines for C or Java, I have noticed that nothing beats enums and switch statements performance-wise, and expressively, they're not that bad, either. Python doesn't have a switch statement, so the natural thing is to ride on method dispatching (whether via inner or outer classes). However, I must say the exception "idiom" someone mentioned on this forum way back has its lure: try: raise self.state except IDLE: #... except SPF_HELO: #... Marko -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
On Fri, May 29, 2015 at 2:59 AM, Marko Rauhamaa wrote: > When I have coded state machines for C or Java, I have noticed that > nothing beats enums and switch statements performance-wise, and > expressively, they're not that bad, either. Python doesn't have a switch > statement, so the natural thing is to ride on method dispatching > (whether via inner or outer classes). However, I must say the exception > "idiom" someone mentioned on this forum way back has its lure: > > try: raise self.state > except IDLE: > #... > except SPF_HELO: > #... I take exception to that idiom. :) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Question About Image Processing in Python
On 28/05/15 11:34, Serge Christian Ibala wrote: I want to know which version of Python is compatible (or can be associated with which version of which "tools or package" for image processing) It would help if you told us what kind of image processing. If you mean programmatic manipulation of images similar to what would be done using GIMP/Photoshop then the most common tools are ImageMagick and Pillow. But you mention neither, so I'm guessing you are looking at doing something else - maybe trying to analyze content? Given the list of tools you list I'd suggest fetching an all-in-one distro like Anaconda or Canopy. That way somebody else does the dependency dance for you. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos -- https://mail.python.org/mailman/listinfo/python-list
Re: Creating a reliable sandboxed Python environment
davidf...@gmail.com schrieb am 26.05.2015 um 04:24: > Has anyone on this list attempted to sandbox Python programs in a > serious fashion? I'd be interested to hear your approach. Not quite sandboxing Python, but I've seen people use my Lupa [1] library for this. They're writing all their code in Python, and then let users embed their own Lua code into it to script their API. The Lua runtime is apparently quite good at sandboxing, and it's really small, just some 600KB or so. Lupa then lets you easily control the access to your Python code at a whitelist level by intercepting all Python attribute lookups. It doesn't add much to your application to embed Lua (or even LuaJIT) in Python, and it gives users a nicely object oriented language to call and orchestrate your Python objects. Stefan [1] https://pypi.python.org/pypi/lupa -- https://mail.python.org/mailman/listinfo/python-list
Re: Creating a reliable sandboxed Python environment
On Fri, May 29, 2015 at 4:41 AM, Stefan Behnel wrote: > davidf...@gmail.com schrieb am 26.05.2015 um 04:24: >> Has anyone on this list attempted to sandbox Python programs in a >> serious fashion? I'd be interested to hear your approach. > > Not quite sandboxing Python, but I've seen people use my Lupa [1] library > for this. They're writing all their code in Python, and then let users > embed their own Lua code into it to script their API. The Lua runtime is > apparently quite good at sandboxing, and it's really small, just some 600KB > or so. Lupa then lets you easily control the access to your Python code at > a whitelist level by intercepting all Python attribute lookups. > > It doesn't add much to your application to embed Lua (or even LuaJIT) in > Python, and it gives users a nicely object oriented language to call and > orchestrate your Python objects. Lua's a much weaker language than Python is, though. Can it handle arbitrary-precision integers? Unicode? Dare I even ask, arbitrary-precision rationals (fractions.Fraction)? Security comes at a price, I guess. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Decoding JSON file using python
On Thu, 28 May 2015 13:32:39 +1000, Cameron Simpson wrote:
> On 28May2015 01:38, Jon Ribbens wrote:
>>On 2015-05-27, Karthik Sharma wrote:
>>> I tried modifying the program as follows as per your
>>> suggestion.Doesn't seem to work.
>>
>>That's because you didn't modify the program as per their suggestion,
>>you made completely different changes that bore no relation to what they
>>said.
>
> Actually, his changes looked good to me. He does print from data first,
> but only for debugging. Then he goes:
>
> message = json.loads(data)
>
> and tried to access message['Message'].
>
> However I am having trouble reproducing his issue because his quoted
> code is incorrect. I've tried to fix it, as listed below, but I don't
> know what is really meant to be in the 'data" string.
it looks like data is a broken array of one object, part of which is a
further quoted json string.
There should be a string value after the isEvent but I have no idea what
it should be, nor what else should come after.
"message":"tdetails":{att:val pairs}
is also wrong in the first level of inner json.
I think he wants data[0]['message'], but the inner json strings are
broken too, and should look more like.
data: "[{\"Severity\":\"warn\",\"Subject\":\"Reporting\",\"Message\":
\"tdetails\",\"attr_name\":\"{\\\"Product\\\":\\\"Gecko\\\",\\\"CPUs\\
\":8,\\\"Language\\\":\\\"en-GB\\\",\\\"isEvent\\\":\\\"attr_value\\\"}\"}
]",
In this model, if the data attribute is a json string, then
data maps to a list / array
data[0] maps to an object / dictionary
data[0]["Message"] maps to the string literal "tdetails"
data[0]["attr_name"] maps to a string representation of a json ob with
another level of escaping.
That string can then be loaded, eg:
attr_name = json.loads(data[0]["attr_name"])
See: http:/www.sined.co.uk/python/nested_json.py.txt
--
Denis McMahon, denismfmcma...@gmail.com
--
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Re: Decoding JSON file using python
On Wed, 27 May 2015 15:23:31 -0700, Karthik Sharma wrote: > The JSON structure is valid as shown by http://jsonlint.com/ Not when I paste it in it's not. The "data" attribute is an unterminated string and is not followed by a comma. -- Denis McMahon, denismfmcma...@gmail.com -- https://mail.python.org/mailman/listinfo/python-list
Logic problem: need better logic for desired thruth table.
Hello, I was just coding and ran into a little logic problem which is as follows: There are two booleans/variables which can be either false or true. The desired thrutle table is: A = input B = input C = output A B C: --- F F T F T F T F T T T T Surpisingly enough I don't think there is a casual/common operator for this thruth table. AND does not apply. OR does not apply. XOR does not apply. So I would need some combined operators to give the desired result. I tried logic below... but funny enough it failed, now I feel like a noob lol and share this funny little fail logic with you. Can you improve/fix the logic ? This is python code, but this^ logic/thruth table problem basically applies to any programming language: # loop has to run if: # while DesiredResult==True: # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # False FalseTrue # False True False # True FalseTrue # True True True # desired/suiting logic: # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) def TestLogic( BotWaitForCooldown, CooldownDetected ): return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. if TestLogic( False, False ) == True: print "test 1 ok" else: print "test 1 failed" if TestLogic( False, True ) == False: print "test 2 ok" else: print "test 2 failed" if TestLogic( True, False ) == True: print "test 3 ok" else: print "test 3 failed" if TestLogic( True, True ) == True: print "test 4 ok" else: print "test 4 failed" Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Pep 484 Type Hint Checker - Python releases supported?
I believe I heard that the PEP 484 type checker is to go into CPython 3.5. Since type annotations have been there since 3.0, is it at all likely that CPython versions < 3.5 will also be supported by this checker? Thanks! -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
I think I have run into this problem before... but solved it with some seperate if statements. However in this case/this time I would like to not solve it with if statements, but simply and/or/not/xor, in other words, boolean operators. So what would help is a "thruth table to logic" convertor/generator ?! Anybody know one that is suited for boolean logic/software programming/programming languages/boolean operations ? Bye, Skybuck. Original posting: "Skybuck Flying" wrote in message news:3794b$55678d83$5419aafe$56...@news.ziggo.nl... Hello, I was just coding and ran into a little logic problem which is as follows: There are two booleans/variables which can be either false or true. The desired thrutle table is: A = input B = input C = output A B C: --- F F T F T F T F T T T T Surpisingly enough I don't think there is a casual/common operator for this thruth table. AND does not apply. OR does not apply. XOR does not apply. So I would need some combined operators to give the desired result. I tried logic below... but funny enough it failed, now I feel like a noob lol and share this funny little fail logic with you. Can you improve/fix the logic ? This is python code, but this^ logic/thruth table problem basically applies to any programming language: # loop has to run if: # while DesiredResult==True: # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # False FalseTrue # False True False # True FalseTrue # True True True # desired/suiting logic: # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) def TestLogic( BotWaitForCooldown, CooldownDetected ): return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. if TestLogic( False, False ) == True: print "test 1 ok" else: print "test 1 failed" if TestLogic( False, True ) == False: print "test 2 ok" else: print "test 2 failed" if TestLogic( True, False ) == True: print "test 3 ok" else: print "test 3 failed" if TestLogic( True, True ) == True: print "test 4 ok" else: print "test 4 failed" Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 2015-05-28 23:50, Skybuck Flying wrote:
> A = input
> B = input
> C = output
>
> A B C:
> ---
> F F T
> F T F
> T F T
> T T T
>
> Surpisingly enough I don't think there is a casual/common operator
> for this thruth table.
>
> AND does not apply.
> OR does not apply.
> XOR does not apply.
Sounds like you want "a or not b"
>>> print("\n".join("A=%s B=%s: %s" % (a, b, a or not b) for a in (True, False)
>>> for b in (True, False)))
A=True B=True: True
A=True B=False: True
A=False B=True: False
A=False B=False: True
-tkc
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Re: Logic problem: need better logic for desired thruth table.
On Thursday, May 28, 2015 at 2:50:18 PM UTC-7, Skybuck Flying wrote: > Hello, > > I was just coding and ran into a little logic problem which is as follows: > > There are two booleans/variables which can be either false or true. > > The desired thrutle table is: > > A = input > B = input > C = output > > A B C: > --- > F F T > F T F > T F T > T T T > > Surpisingly enough I don't think there is a casual/common operator for this > thruth table. > > AND does not apply. > OR does not apply. > XOR does not apply. > > So I would need some combined operators to give the desired result. > > I tried logic below... but funny enough it failed, now I feel like a noob > lol and share this funny little fail logic with you. > > Can you improve/fix the logic ? > > This is python code, but this^ logic/thruth table problem basically applies > to any programming language: > > # loop has to run if: > # while DesiredResult==True: > # Desired truth table for BotWaitForCooldown and CooldownDetected > # BotWaitForCooldown: CooldownDetected: Desired Result: > # False FalseTrue > # False True False > # True FalseTrue > # True True True > # desired/suiting logic: > # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) > > def TestLogic( BotWaitForCooldown, CooldownDetected ): > return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) > # this logic is flawed, please improve logic. > > if TestLogic( False, False ) == True: > print "test 1 ok" > else: > print "test 1 failed" > > if TestLogic( False, True ) == False: > print "test 2 ok" > else: > print "test 2 failed" > > if TestLogic( True, False ) == True: > print "test 3 ok" > else: > print "test 3 failed" > > if TestLogic( True, True ) == True: > print "test 4 ok" > else: > print "test 4 failed" > > Bye, > Skybuck. I think the logic you're really looking for is: return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 2015-05-28, Skybuck Flying wrote: > I tried logic below... but funny enough it failed, now I feel like a > noob lol and share this funny little fail logic with you. > > Can you improve/fix the logic ? > # while DesiredResult==True: > # Desired truth table for BotWaitForCooldown and CooldownDetected > # BotWaitForCooldown: CooldownDetected: Desired Result: > # FalseFalse True > # FalseTrue False > # True False True > # True True True > # desired/suiting logic: > # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) I don't see why you think that's the desired logic, since it doesn't match your truth table or your test. > def TestLogic( BotWaitForCooldown, CooldownDetected ): > return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) > # this logic is flawed, please improve logic. def TestLogic( BotWaitForCooldown, CooldownDetected ): return not ((not BotWaitForCooldown) and CooldownDetected) works for me... -- Grant Edwards grant.b.edwardsYow! Alright, you!! at Imitate a WOUNDED SEAL gmail.compleading for a PARKING SPACE!! -- https://mail.python.org/mailman/listinfo/python-list
Re: Pep 484 Type Hint Checker - Python releases supported?
On Thu, May 28, 2015 at 4:58 PM, Dan Stromberg wrote: > I believe I heard that the PEP 484 type checker is to go into CPython 3.5. > > Since type annotations have been there since 3.0, is it at all likely > that CPython versions < 3.5 will also be supported by this checker? All that's going into 3.5 is the typing.py module, which will also be distributed on PyPI. The actual type checking is being left to third-party tools like MyPy (which was the basis for the typing.py module). I'm not sure if there is any plan to ever include an actual type checker with the base Python distribution. -- Zach -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
This is a start lol: https://www.youtube.com/watch?v=lKqTSBKmWA4 I wonder if it can be simplied... I'll give it a try. Basically it comes down to creating a logic expression for each true result in the desired output and or-ing with each other. The variables leading to the true result in the desired output need to be kept if true, and negated if false. So for example: A B C F T T ((NOT A) AND (B) AND ETC) OR ETC. What the video didn't really explain is probably to "and" the variables... but it did mention "multiply". I guess "AND" is the closest thing to a multiply ;) Makes sense... only AND gives a 1 output if all variables are true, otherwise it would zero out... Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
However I can already see I am not happy with this video solution. I have 3 true outputs, and only 1 false output. That would require a lot of logic. I guess I can turn it around and negate the whole thing... and focus on the false output. Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
Skybuck Flying writes: > There are two booleans/variables which can be either false or true. > > The desired thrutle table is: > > A = input > B = input > C = output > > A B C: > --- > F F T > F T F > T F T > T T T That's A >= B, where True >= False: >>> BB = False, True >>> print(*((A, B, A >= B) for A in BB for B in BB), sep = '\n') (False, False, True) (False, True, False) (True, False, True) (True, True, True) >>> -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 2015-05-28, Grant Edwards wrote: > On 2015-05-28, Skybuck Flying wrote: > >> I tried logic below... but funny enough it failed, now I feel like a >> noob lol and share this funny little fail logic with you. >> >> Can you improve/fix the logic ? > >> # while DesiredResult==True: >> # Desired truth table for BotWaitForCooldown and CooldownDetected >> # BotWaitForCooldown: CooldownDetected: Desired Result: >> # FalseFalse True >> # FalseTrue False >> # True False True >> # True True True >> # desired/suiting logic: >> # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) > > I don't see why you think that's the desired logic, since it doesn't > match your truth table or your test. > >> def TestLogic( BotWaitForCooldown, CooldownDetected ): >> return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) >> # this logic is flawed, please improve logic. > > def TestLogic( BotWaitForCooldown, CooldownDetected ): > return not ((not BotWaitForCooldown) and CooldownDetected) > > works for me... While I think that's the most "obvious" solution and can be verified by inspection: there's only out input state that is "false", so write an expression for that one state and invert it. However, you can apply De Morgan's law to simplify it: not ((not BotWaitForCooldown) and CooldownDetected) is same as (BotWaitForCooldown or (not CooldownDetected)) -- Grant Edwards grant.b.edwardsYow! Do you have exactly at what I want in a plaid gmail.compoindexter bar bat?? -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
On 2015-05-28, Skybuck Flying wrote: > However I can already see I am not happy with this video solution. > > I have 3 true outputs, and only 1 false output. > > That would require a lot of logic. > > I guess I can turn it around and negate the whole thing... and focus on the > false output. Don't they teach Karnaugh mapping any more? http://en.wikipedia.org/wiki/Karnaugh_map -- Grant Edwards grant.b.edwardsYow! I want the presidency at so bad I can already taste gmail.comthe hors d'oeuvres. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
Ok, problem solved for now, it seems: I used video tutorial method and inverted it for the false case ;) But anyway... I would not only need a "thruth table to logic/boolean operations converter" but also a "boolean operations optimizer" ;) # loop has to run if: # while DesiredResult==True: # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # False FalseTrue # False True False # True FalseTrue # True True True # desired/suiting logic: # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) def TestLogic( BotWaitForCooldown, CooldownDetected ): # return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. return (not ((not BotWaitForCooldown) and CooldownDetected)) # fixes it. if TestLogic( False, False ) == True: print "test 1 ok" else: print "test 1 failed" if TestLogic( False, True ) == False: print "test 2 ok" else: print "test 2 failed" if TestLogic( True, False ) == True: print "test 3 ok" else: print "test 3 failed" if TestLogic( True, True ) == True: print "test 4 ok" else: print "test 4 failed" Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 05/28/2015 03:58 PM, sohcahto...@gmail.com wrote: > I think the logic you're really looking for is: > > return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) Yes this is the simplest form. For more complicated truth tables you can create a K map and then apply a reduction algorithm to it. This is commonly done in logic circuits to reduce the number of gates to the minimum. While not faster, it can be expressed as: return BotWaitForCooldown or not BotWaitForCooldown and not CooldownDectected Order of operations puts the ands above the ors. -- https://mail.python.org/mailman/listinfo/python-list
Re: Accessing DataSocket Server with Python
I have no idea about the protocol used by NI DataSockets, but you might be able to reverse engineer the protocol by using the official client with a sniffer. Also, be aware that TCP/IP guarantees that you get the correct data in the correct order, but it doesn't guarantee anything about the sizes of the chunks in which that data arrives. So you could send 100 bytes, 100 bytes, 100 bytes, but on the other end receive 100 bytes, 50 bytes, 75 bytes, 75 bytes. When you catenate them all together, it's still the same data though. HTH. On Wed, May 27, 2015 at 4:30 AM, Garrone, Corrado wrote: > Dear Python Team, > > currently I am working on a research project for my bachelor degree. A > LabVIEW application is used for current and power measurements, whereas the > measured data are sent to DataSocket Server, a technology by National > Instruments used for data exchange between computers and applications. > DataSocket is based on TCP/IP and thus requesting data from DataSocket > should be similar to an internet request. > I know with the socket library in Python it is possible with to establish > sockets, send internet requests and communicate between clients and servers. > Is there a possibility to access NI DataSocket and get measurement data with > Python on the same computer where Python is installed and the codes are > executed? Can you maybe send me an example code where such a connection with > DataSocket is established? > > If you got any queries, please do not hesitate to contact me. > > Thank you very much for your efforts. > > Kind regards, > > Corrado Garrone > DH-Student Fachrichtung Elektrotechnik / Co-op Student B.Eng. Electrical > Engineering > > Roche Diagnostics GmbH > DFGHMV8Y6164 > Sandhofer Strasse 116 > 68305 Mannheim / Germany > > Phone: apprentice > mailto:corrado.garr...@roche.com > > Roche Diagnostics GmbH > Sandhofer Straße 116; D‑68305 Mannheim; Telefon +49‑621‑759‑0; Telefax > +49‑621‑759‑2890 > Sitz der Gesellschaft: Mannheim - Registergericht: AG Mannheim HRB 3962 - > Geschäftsführung: Dr. Ursula Redeker, Sprecherin; Edgar Vieth - > Aufsichtsratsvorsitzender: Dr. Severin Schwan > > Confidentiality Note > This message is intended only for the use of the named recipient(s) and may > contain confidential and/or privileged information. If you are not the > intended recipient, please contact the sender and delete the message. Any > unauthorized use of the information contained in this message is prohibited. > > > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
On 2015-05-28, Grant Edwards wrote: > On 2015-05-28, Skybuck Flying wrote: > >> However I can already see I am not happy with this video solution. >> >> I have 3 true outputs, and only 1 false output. >> >> That would require a lot of logic. >> >> I guess I can turn it around and negate the whole thing... and focus on the >> false output. > > Don't they teach Karnaugh mapping any more? > > http://en.wikipedia.org/wiki/Karnaugh_map BTW, your example truth table is shown in the paragraph '2-variable map examples' -- Grant Edwards grant.b.edwardsYow! Oh my GOD -- the at SUN just fell into YANKEE gmail.comSTADIUM!! -- https://mail.python.org/mailman/listinfo/python-list
Re: Pep 484 Type Hint Checker - Python releases supported?
On Fri, May 29, 2015 at 8:06 AM, Zachary Ware wrote: > On Thu, May 28, 2015 at 4:58 PM, Dan Stromberg wrote: >> I believe I heard that the PEP 484 type checker is to go into CPython 3.5. >> >> Since type annotations have been there since 3.0, is it at all likely >> that CPython versions < 3.5 will also be supported by this checker? > > All that's going into 3.5 is the typing.py module, which will also be > distributed on PyPI. The actual type checking is being left to > third-party tools like MyPy (which was the basis for the typing.py > module). > > I'm not sure if there is any plan to ever include an actual type > checker with the base Python distribution. And MyPy is quite capable of probing code that belongs on older interpreters than 3.5 (obviously, since it already exists); it even has some measure of support for probing Py2 code, although you do need to have a Python 3.2+ to actually run MyPy on. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Thursday May 28 2015 17:50, in comp.lang.c, "Skybuck Flying"
wrote:
> Hello,
>
> I was just coding and ran into a little logic problem which is as follows:
>
> There are two booleans/variables which can be either false or true.
>
> The desired thrutle table is:
>
> A = input
> B = input
> C = output
>
> A B C:
> ---
> F F T
> F T F
> T F T
> T T T
Seems simple enough: C == A || !B
18:38 $ cat testlogic.c
#include
#include
/*
** A = input
** B = input
** C = output
**
** A B C:
** ---
** F F T
** F T F
** T F T
** T T T
*/
int testlogic(int a, int b)
{
return (a || !b);
}
int main(void)
{
/* A B C */
int ttable[4][3] = { {0,0,1},/* F F T */
{0,1,0},/* F T F */
{1,0,1},/* T F T */
{1,1,1} /* T T T */
};
int rc = EXIT_SUCCESS;
int i, max;
for (i = 0, max = sizeof(ttable) / sizeof(ttable[0]); i < max ; ++i)
if (testlogic(ttable[i][0],ttable[i][1]) != ttable[i][2])
{
printf("testlogic failed on test %d\n",i);
rc = EXIT_FAILURE;
}
if (rc == EXIT_SUCCESS) puts("SUCCESS");
return rc;
}
18:39 $ cc -o testlogic testlogic.c
18:39 $ ./testlogic
SUCCESS
--
Lew Pitcher
"In Skills, We Trust"
PGP public key available upon request
--
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[no subject]
hola, escribo para solicitar el uso del programa Python para trabajarlo con mi hijo. desde ya muchas gracias Enviado desde Correo de Windows-- https://mail.python.org/mailman/listinfo/python-list
Re:
2015-05-29 9:44 GMT+10:00 yasna araya : > hola, escribo para solicitar el uso del programa Python para trabajarlo con > mi hijo. desde ya muchas gracias > > Enviado desde Correo de Windows Hello! This is an English-language list, and most of the people here - myself included - are not fluent in Spanish. But you can download Python from here: https://www.python.org/downloads/ If that wasn't what you were looking for, I apologize; possibly someone else here speaks better Spanish, or perhaps you could rephrase your question in English. All the best! ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 2015-05-28, Michael Torrie wrote: > On 05/28/2015 03:58 PM, sohcahto...@gmail.com wrote: >> I think the logic you're really looking for is: >> >> return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) > > Yes this is the simplest form. Not really. In old school notation, that's ___ A + A+B Apply De Morgan's law to the second term _ _ A + (A * B) Invert _ _ A + (A*B) Apply Demorgan's law once _ __ _ A * (A * B) and again for the second term _ A * (A + B) Apply the distributive property: _ _ A*A + A*B The first term is always false, so we can drop it: _ A*B Now invert it again to cancel out the one we did back a few steps: ___ _ A*B De Morgan one last time: _ A + B -- Grant Edwards grant.b.edwardsYow! Xerox your lunch at and file it under "sex gmail.comoffenders"! -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 28/05/2015 23:39, Lew Pitcher wrote:
On Thursday May 28 2015 17:50, in comp.lang.c, "Skybuck Flying"
wrote:
Hello,
I was just coding and ran into a little logic problem which is as follows:
There are two booleans/variables which can be either false or true.
The desired thrutle table is:
A = input
B = input
C = output
A B C:
---
F F T
F T F
T F T
T T T
Seems simple enough: C == A || !B
18:38 $ cat testlogic.c
#include
#include
/*
** A = input
** B = input
** C = output
**
** A B C:
** ---
** F F T
** F T F
** T F T
** T T T
*/
int testlogic(int a, int b)
{
return (a || !b);
}
int main(void)
{
/* A B C */
int ttable[4][3] = { {0,0,1},/* F F T */
{0,1,0},/* F T F */
{1,0,1},/* T F T */
{1,1,1} /* T T T */
};
int rc = EXIT_SUCCESS;
int i, max;
for (i = 0, max = sizeof(ttable) / sizeof(ttable[0]); i < max ; ++i)
if (testlogic(ttable[i][0],ttable[i][1]) != ttable[i][2])
{
printf("testlogic failed on test %d\n",i);
rc = EXIT_FAILURE;
}
if (rc == EXIT_SUCCESS) puts("SUCCESS");
return rc;
}
18:39 $ cc -o testlogic testlogic.c
18:39 $ ./testlogic
SUCCESS
Strangest looking Python I've ever seen. Or is it a case of "Get thee
behind me, Satan" :)
--
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.
Mark Lawrence
--
https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 2015-05-28, Grant Edwards wrote: > On 2015-05-28, Michael Torrie wrote: >> On 05/28/2015 03:58 PM, sohcahto...@gmail.com wrote: >>> I think the logic you're really looking for is: >>> >>> return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) >> >> Yes this is the simplest form. > > Not really. > > > In old school notation, that's > ___ > A + A+B > > [...] That derivation was excessively round-about. Here is the same thing in fewer steps: Invert: ___ ___ A + A+B De Morgan: _ A * (A + B) Distribute: _ _ A*A + A*B Drop the null term: _ A*B Invert (to cancel out the first step) ___ _ A*B De Morgan: _ A+B -- Grant Edwards grant.b.edwardsYow! I'm reporting for duty at as a modern person. I want gmail.comto do the Latin Hustle now! -- https://mail.python.org/mailman/listinfo/python-list
Re:
Hola Yasna Chris te escribe que puedes bajar la solución Python desde este link: https://www.python.org/downloads/ También escribe que el foro es en inglés ya que la mayoría de las personas que forman parte de la lista hablan inglés. Saludos y éxitos Translated: Hi Yasna Chris wrote that you can download Python from the following link: https://www.python.org/downloads/ He also wrote that this forum is in english because the majority of the people that are part of the list also speak english. Regards On Thu, May 28, 2015 at 6:20 PM, Chris Angelico wrote: > 2015-05-29 9:44 GMT+10:00 yasna araya : > > hola, escribo para solicitar el uso del programa Python para trabajarlo > con > > mi hijo. desde ya muchas gracias > > > > Enviado desde Correo de Windows > > Hello! > > This is an English-language list, and most of the people here - myself > included - are not fluent in Spanish. But you can download Python from > here: > > https://www.python.org/downloads/ > > If that wasn't what you were looking for, I apologize; possibly > someone else here speaks better Spanish, or perhaps you could rephrase > your question in English. > > All the best! > > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
refer to xpath attributes generally
Is there a way to specify to all attributes in xpath? Instead of directly Eg //element/@attr So that you could effectively loop and filter if an element had more than one Attribute? So items = tree.xpath(@all_attrs) >From lxml import etree Tree = etree.Xpath(//root) For k, v in items: Choose your k's Thanks for your time in advance Please forgive some formatting errors phone auto correct Sayth -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
Skybuck Flying wrote: Hello, I was just coding and ran into a little logic problem which is as follows: There are two booleans/variables which can be either false or true. The desired thrutle table is: A = input B = input C = output A B C: --- F F T F T F T F T T T T Surpisingly enough I don't think there is a casual/common operator for this thruth table. AND does not apply. OR does not apply. XOR does not apply. So I would need some combined operators to give the desired result. I tried logic below... but funny enough it failed, now I feel like a noob lol and share this funny little fail logic with you. Can you improve/fix the logic ? This is python code, but this^ logic/thruth table problem basically applies to any programming language: # loop has to run if: # while DesiredResult==True: # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # False FalseTrue # False True False # True FalseTrue # True True True # desired/suiting logic: # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) def TestLogic( BotWaitForCooldown, CooldownDetected ): return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. if TestLogic( False, False ) == True: print "test 1 ok" else: print "test 1 failed" if TestLogic( False, True ) == False: print "test 2 ok" else: print "test 2 failed" if TestLogic( True, False ) == True: print "test 3 ok" else: print "test 3 failed" if TestLogic( True, True ) == True: print "test 4 ok" else: print "test 4 failed" Bye, Skybuck. If you ever have a really complicated truth table, you can use Quine McCluskey minimization. At work, I had no tool for minimizing boolean equations, so I got some code from another engineer, code that ran on a mainframe computer. And I converted the code to run on a personal computer. The computers were so slow back then, it might take ten to fifteen minutes to minimize a ten variable truth table. On the mainframe you could have a 2MB array for storage, whereas on my personal computer at the time, the memory was segmented and required some tricks to get enough. http://en.wikipedia.org/wiki/Quine%E2%80%93McCluskey_algorithm If it isn't a scam, the source code should be reasonably short. The program I was using, might have been on the order of 120 lines of source. This example is a bit longer, and the couple programs I've been looking at the source, I don't recognize what they're doing. http://sourceforge.net/projects/mini-qmc/files/?source=navbar Your problem isn't large enough to need this sort of thing, but I thought I'd throw it in as a topic of general interest. If it's one thing I've learned over the years, hand-optimization of boolean equations frequently leads to errors. And it's when you start engaging your brain, and saying stuff like "I know the answer", instead of sticking with your boolean algebra, that errors creep in. If you need a test case for your QM code, enter an "XOR tree", as an XOR tree is irreducible and should cough out the same info, as you entered in the first place. That was one of my test cases, when porting the code maybe 30 years ago. (And no, I didn't keep a copy of the code. We didn't do stuff like that back then. I didn't even have a computer at home back then.) Paul -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Thu, 28 May 2015 14:58:19 -0700, sohcahtoa82 wrote: > On Thursday, May 28, 2015 at 2:50:18 PM UTC-7, Skybuck Flying wrote: >> Hello, >> # Desired truth table for BotWaitForCooldown and CooldownDetected >> # BotWaitForCooldown: CooldownDetected: Desired Result: >> # FalseFalse True >> # FalseTrue False >> # True False True >> # True True True > I think the logic you're really looking for is: > return BotWaitForCooldown or (not (BotWaitForCooldown or > CooldownDetected)) Nope, it simplifies to: BotWaitForCooldown or not CooldownDetected -- Denis McMahon, denismfmcma...@gmail.com -- https://mail.python.org/mailman/listinfo/python-list
Getting an image from a file on windows
Hello, I have been working on a function that gets a bitmap of the thumbnail for a file. I have had problems getting a large image (256x256) and I was wondering if someone could help me on one object initialization that is driving me nuts. I have code here: https://gist.github.com/IronManMark20/a83fe7ff7ea9b40c09af I need to initialize a *void pointer for the third argument for SHGetImageList (ref https://msdn.microsoft.com/en-us/library/bb762185). What should the initialization look like (please give me example code, not just "Oh it should be a ctypes.c_void_p"). Thanks!!! -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Thursday, May 28, 2015 at 3:17:10 PM UTC-7, Michael Torrie wrote: > On 05/28/2015 03:58 PM, sohcahto...@gmail.com wrote: > > I think the logic you're really looking for is: > > > > return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) > > Yes this is the simplest form. For more complicated truth tables you > can create a K map and then apply a reduction algorithm to it. This is > commonly done in logic circuits to reduce the number of gates to the > minimum. While not faster, it can be expressed as: > > return BotWaitForCooldown or not BotWaitForCooldown and not > CooldownDectected > > Order of operations puts the ands above the ors. Order of operations might put the ands above the ors, but I still like using parentheses in expressions like that as I think it makes it more clear. -- https://mail.python.org/mailman/listinfo/python-list
Re: Getting an image from a file on windows
On 2015-05-29 01:03, IronManMark20 wrote: Hello, I have been working on a function that gets a bitmap of the thumbnail for a file. I have had problems getting a large image (256x256) and I was wondering if someone could help me on one object initialization that is driving me nuts. I have code here: https://gist.github.com/IronManMark20/a83fe7ff7ea9b40c09af I need to initialize a *void pointer for the third argument for SHGetImageList (ref https://msdn.microsoft.com/en-us/library/bb762185). What should the initialization look like (please give me example code, not just "Oh it should be a ctypes.c_void_p"). Thanks!!! Have you tried byref(hico)? -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On 05/28/2015 05:03 PM, Grant Edwards wrote: > On 2015-05-28, Grant Edwards wrote: >> On 2015-05-28, Michael Torrie wrote: >>> On 05/28/2015 03:58 PM, sohcahto...@gmail.com wrote: I think the logic you're really looking for is: return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) >>> >>> Yes this is the simplest form. >> >> Not really. True enough. My skills from EE are pretty rusty. -- https://mail.python.org/mailman/listinfo/python-list
Re: Getting an image from a file on windows
On Thursday, May 28, 2015 at 5:37:07 PM UTC-7, MRAB wrote: > On 2015-05-29 01:03, IronManMark20 wrote: > > Hello, > > > > I have been working on a function that gets a bitmap of the thumbnail > > for a file. I have had problems getting a large image (256x256) and I > > was wondering if someone could help me on one object initialization > > that is driving me nuts. > > > > I have code here: > > https://gist.github.com/IronManMark20/a83fe7ff7ea9b40c09af > > > > I need to initialize a *void pointer for the third argument for > > SHGetImageList (ref > > https://msdn.microsoft.com/en-us/library/bb762185). > > > > What should the initialization look like (please give me example > > code, not just "Oh it should be a ctypes.c_void_p"). > > > > Thanks!!! > > > Have you tried byref(hico)? Thanks so much! That seems to have done it. Now I get to figure out how to get the image. -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
On Fri, 29 May 2015 01:01 am, Marko Rauhamaa wrote:
> Anssi Saari :
>
>> Do you have an example of state pattern using nested classes and
>> python? With a quick look I didn't happen to find one in any language.
>
> Here's an sampling from my mail server:
I haven't studied this in close detail, but first impressions is that this
is not well-written Python code. The obvious problems that come to mind:
> class SMTPServerConnection(ServerConnection):
> #: : :
> #: : :
>
> def __init__(self, server, sock, domain, peer):
> super().__init__(server, sock)
> conn = self
> client_ip = peer[0]
>
> class STATE:
> def __str__(self):
> return self.__class__.__name__
A minor criticism: each time you instantiate a new SMTP server connection,
it creates new STATE, IDLE etc. classes. That's wasteful and inefficient
unless you have a good reason for it, although you may not care if you only
have a single connection at a time.
More serious problem: by nesting the state classes, it is much harder to
test the state classes in isolation from a connection.
> def handle_command(self, cmd):
> conn.log("handle_command (unexpected): {}".format(cmd))
> assert False
At first glance, this appears to be an abuse of `assert` and risks breaking
your code when running under -O which turns debugging (and hence asserts)
off. Since the intent is to make these abstract methods which must be
overridden, I'd prefer to define an AbstractMethodError, then:
raise AbstractMethodError("unexpected %s" % cmd)
then do the logging elsewhere.
This has the advantage(?) of eliminating the need to refer to conn, which
means that the methods are no longer closures and the entire inner class
can be moved out of the SMTPServerConnection body.
[...]
> class IDLE(STATE):
> def handle_command(self, cmd):
> conn.log("handle_command: {}".format(cmd))
Using a closure for information hiding is a solid functional equivalent to
using private fields in an OOP context. However, "private" should be
considered an anti-testing idiom. I would seriously consider this entire
design to be an anti-pattern, and would prefer to one of two alternate
designs:
(1) Pull the state classes out of the SMTPServerConnection class. On
initialisation, each state takes a conn argument. All references to "conn"
are replaced by "self.conn". That's basically the conventional OOP
approach.
(2) Again, pull the state classes out of the SMTPServerConnection class,
except this time there is no need to instantiate the state classes at all!
Decorate all the methods with @classmethod, and have them take the
connection as an explicit argument. The caller (namely the
SMTPServerConnection instance) provides itself as argument to the state
methods, like so:
self.state = IDLE # No need to instantiate.
self.state.process_ehlo_or_helo(self, other, args, go, here)
This reduces implicit coupling, makes it explicit that the state methods
depend on the connection, avoids reference loops, and enables easy mocking
for testing.
The only downsides are that people coming from a conventional (e.g. Java)
OOP background will freak at seeing you using a class as a first class
value (pun intended), and it will be ever-so-slightly tiresome to have to
decorate each and every method with classmethod.
(Perhaps a class decorator is the solution to that second issue?)
The "design pattern" community is dominated by Java, where classes are not
values, so this idiom is impossible in Java and unlikely to have a DP name.
But it really should have one -- in a language where classes are themselves
values, there is no reason why a class *must* be instantiated, particularly
if you're only using a single instance of the class. Anyone ever come
across a named design pattern that involves using classes directly without
instantiating them?
I'm basically looking for a less inelegant term for "instanceless class" --
not so much a singleton as a zeroton.
--
Steven
--
https://mail.python.org/mailman/listinfo/python-list
Re: refer to xpath attributes generally
On Friday, 29 May 2015 09:21:01 UTC+10, Sayth Renshaw wrote:
> Is there a way to specify to all attributes in xpath? Instead of directly Eg
> //element/@attr
>
> So that you could effectively loop and filter if an element had more than one
> Attribute?
>
> So items = tree.xpath(@all_attrs)
>
> From lxml import etree
>
> Tree = etree.Xpath(//root)
>
> For k, v in items:
> Choose your k's
>
>
> Thanks for your time in advance
> Please forgive some formatting errors phone auto correct
> Sayth
It appears this is the best answer
n [17]: with open('C:/Users/Sayth/Desktop/20150530RHIL0.xml', 'rb') as f:
: tree = etree.parse(f)
: for attrResult in tree.xpath('/meeting/race/@*'):
: print(attrResult.attrname)
--
https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
Interestingly enough the shortest I have seen so far is ***: def TestLogic( BotWaitForCooldown, CooldownDetected ): # return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. # return (not ((not BotWaitForCooldown) and CooldownDetected)) # fixes it. # return (BotWaitForCooldown or (not CooldownDetected)) # optimization but looks weird :) return (BotWaitForCooldown >= CooldownDetected) # *** even shorter, wow cool, thanks to Jussi Piitulainen Apperently there is a short-coming/flaw in the reasoning about boolean logic, if boolean logic is converted to numbers/0/1 and comparisions allowed then apperently there are even shorter forms ?!? Am I correct ? Or am I missing something ? Perhaps branching don't count ? H. Is this branching ? Or something else... hmmm I think the comparison result could be used without requiring branching... so I think my conclusion might be correct. Bye, Skybuck. "Skybuck Flying" wrote in message news:7b1ef$556792ab$5419aafe$58...@news.ziggo.nl... Ok, problem solved for now, it seems: I used video tutorial method and inverted it for the false case ;) But anyway... I would not only need a "thruth table to logic/boolean operations converter" but also a "boolean operations optimizer" ;) # loop has to run if: # while DesiredResult==True: # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # False FalseTrue # False True False # True FalseTrue # True True True # desired/suiting logic: # (BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected)) def TestLogic( BotWaitForCooldown, CooldownDetected ): # return BotWaitForCooldown or ((not BotWaitForCooldown) and CooldownDetected) # this logic is flawed, please improve logic. return (not ((not BotWaitForCooldown) and CooldownDetected)) # fixes it. if TestLogic( False, False ) == True: print "test 1 ok" else: print "test 1 failed" if TestLogic( False, True ) == False: print "test 2 ok" else: print "test 2 failed" if TestLogic( True, False ) == True: print "test 3 ok" else: print "test 3 failed" if TestLogic( True, True ) == True: print "test 4 ok" else: print "test 4 failed" Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
"Denis McMahon" wrote in message news:mk884e$gth$1...@dont-email.me... On Thu, 28 May 2015 14:58:19 -0700, sohcahtoa82 wrote: On Thursday, May 28, 2015 at 2:50:18 PM UTC-7, Skybuck Flying wrote: Hello, # Desired truth table for BotWaitForCooldown and CooldownDetected # BotWaitForCooldown: CooldownDetected: Desired Result: # FalseFalse True # FalseTrue False # True False True # True True True I think the logic you're really looking for is: return BotWaitForCooldown or (not (BotWaitForCooldown or CooldownDetected)) " Nope, it simplifies to: BotWaitForCooldown or not CooldownDetected " Apperently it can be simplied even further: BotWaitForCooldown >= CooldownDetected Interesting isn't it ? :) Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table. (thruth table to logic/boolean operations generator sought/needed)
I am not so sure anymore about my conclusion, I will investigate this further tomorrow. It seems safe to conclude that at least the following operators have their own thruth tables: = <> < = <= These are the comparision operators. Assume True is greater than False allows them to be used as well. The question that remains is: How many "gates" or "basic" operations or "wires" would they require. Are some of these perhaps very "efficient" and could thus lead to even shorter gate designs ? However for my purposes, reducing code, the answer is already: YES For software logic/boolean reduction the answer is already YES, funny and interestingly enough ! ;) :) Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Thu, May 28, 2015, at 17:50, Skybuck Flying wrote: > Surpisingly enough I don't think there is a casual/common operator for > this > thruth table. > > AND does not apply. > OR does not apply. > XOR does not apply. All sixteen possible logical operators have formal names. This one is called "B implies A". It can be implemented, as others have mentioned with "A or not B". The possibility of spelling these with the comparison operators, as some have suggested, is a consequence of Python's implementation where True == 1 and False == 0. In other languages bool may not be relatable (or at least not orderable), or False may be == -1. -- https://mail.python.org/mailman/listinfo/python-list
Re: Getting an image from a file on windows
On Thursday, May 28, 2015 at 5:37:07 PM UTC-7, MRAB wrote: > On 2015-05-29 01:03, IronManMark20 wrote: > > Hello, > > > > I have been working on a function that gets a bitmap of the thumbnail > > for a file. I have had problems getting a large image (256x256) and I > > was wondering if someone could help me on one object initialization > > that is driving me nuts. > > > > I have code here: > > https://gist.github.com/IronManMark20/a83fe7ff7ea9b40c09af > > > > I need to initialize a *void pointer for the third argument for > > SHGetImageList (ref > > https://msdn.microsoft.com/en-us/library/bb762185). > > > > What should the initialization look like (please give me example > > code, not just "Oh it should be a ctypes.c_void_p"). > > > > Thanks!!! > > > Have you tried byref(hico)? Could you suggest how I could get an hIcon from the newly drawn image? I have been trying, but I haven't found anything. -- https://mail.python.org/mailman/listinfo/python-list
Fixing Python install on the Mac after running 'CleanMyMac'
webmas...@python.org just got some mail from some poor embarrased soul who ran this program and broke their Python install. They are running Mac OSX 10.7.5 They are getting: Utility has encountered a fatal error, and will now terminate. A Python runtime could not be located. You may need to install a framework build of Python or edit the PyRuntimeLocations array in this applications info.plist file. Then there are two oblong circles. One says Open Console. The other says Terminate. So https://docs.python.org/2/using/mac.html says: The Apple-provided build of Python is installed in /System/Library/Frameworks/Python.framework and /usr/bin/python, respectively. You should never modify or delete these, as they are Apple-controlled and are used by Apple- or third-party software. So, I assume this poor soul has done precisely that. What do I tell her to do now? Laura -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Fri, May 29, 2015 at 1:20 PM, wrote: > The possibility of spelling these with the comparison operators, as some > have suggested, is a consequence of Python's implementation where True > == 1 and False == 0. In other languages bool may not be relatable (or at > least not orderable), or False may be == -1. True. That said, though, using 0 for False and 1 for True is easily the most common convention in use today, and the next most likely case is that comparing booleans would give a simple and immediate error. So it's most likely to be safe to do. Cross-language compatibility is a tricky thing anyway; there are all sorts of odd edge cases, even with otherwise-similar languages (Pike and Python, for instance, have slightly different handling of slice ranges), so anything that's done in Python is meant to be interpreted with Python semantics. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
wrote in message news:mailman.152.1432869623.5151.python-l...@python.org... On Thu, May 28, 2015, at 17:50, Skybuck Flying wrote: Surpisingly enough I don't think there is a casual/common operator for this thruth table. AND does not apply. OR does not apply. XOR does not apply. " All sixteen possible logical operators have formal names. This one is called "B implies A". It can be implemented, as others have mentioned with "A or not B". " Ok thanks for this information. I was just wondering how many thruth table combinations there can be for a typical thruth table with 2 inputs and 1 output. Since there are 2 inputs, this means 4 possible outputs, which means 2 to the power of 4 different thruth tables possible, which is indeed 16. Perhaps you have a link to all possible 16 thruth tables and their formal names ? That would help ! Bye, Skybuck. -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
You may be interested in PyEda https://pypi.python.org/pypi/pyeda It is for electronic design automation. But it will minimise truth tables for you. http://pyeda.readthedocs.org/en/latest/search.html?q=truth+tables&check_keywords=yes&area=default Laura -- https://mail.python.org/mailman/listinfo/python-list
Re:
Chris. Este grupo es en Ingles. La verdad no se si existen grupos en español, pero juraria que si. Entiendo que quieres enseñarle python a tu hijo. Aca te envio algunos recursos. Espero que te sirvan: https://silvercorp.wordpress.com/2012/05/27/pasos-de-instalacion-de-python-en-windows/ http://www.slideshare.net/CAChemE/instalar-python-27-y-3-en-windows-anaconda https://devcode.la/tutoriales/instalacion-de-python-27-en-windows-8/ http://codehero.co/python-desde-cero-instalacion-y-configuracion/ http://codehero.co/series/python-desde-cero.html http://www.ehowenespanol.com/instalar-python-windows-como_44790/ https://www.youtube.com/watch?v=NEo4tDu6tU8 http://es.diveintopython.net/toc.html http://mundogeek.net/tutorial-python/ http://pyspanishdoc.sourceforge.net/index.html https://www.youtube.com/watch?v=GbfXj0iQQH0 https://www.youtube.com/watch?v=W7xZvUQhQWg https://www.youtube.com/watch?v=DVD17s7hAj8 -- https://mail.python.org/mailman/listinfo/python-list
[no subject]
Sabe usted acerca de estas páginas? https://mail.python.org/mailman/listinfo/python-es https://wiki.python.org/moin/SpanishLanguage Laura -- https://mail.python.org/mailman/listinfo/python-list
Re: should "self" be changed?
On Fri, 29 May 2015 12:00 pm, Steven D'Aprano wrote: > I haven't studied this in close detail, but first impressions is that this > is not well-written Python code. The obvious problems that come to mind: Well, first impressions can be misleading... I wrote the above, thinking that there were more problems with the code than there actually are. (Specifically, I didn't notice that the inner classes used closures for their methods, then forgot to go back and revise that sentence.) So the code actually was not as bad as I first thought, not withstanding the issues that I described in my previous post. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Logic problem: need better logic for desired thruth table.
On Fri, 29 May 2015 01:49 pm, Skybuck Flying wrote: > wrote in message > news:mailman.152.1432869623.5151.python-l...@python.org... > > On Thu, May 28, 2015, at 17:50, Skybuck Flying wrote: >> Surpisingly enough I don't think there is a casual/common operator for >> this >> thruth table. >> >> AND does not apply. >> OR does not apply. >> XOR does not apply. > > " > All sixteen possible logical operators have formal names. This one is > called "B implies A". It can be implemented, as others have mentioned > with "A or not B". > " > > Ok thanks for this information. > > I was just wondering how many thruth table combinations there can be for a > typical thruth table with 2 inputs and 1 output. The word is TRUTH not THRUTH. I don't know if you're a native English speaker, but "thruth" sounds like the name of a bird (thrush) spoken with a lisp. > Since there are 2 inputs, this means 4 possible outputs, which means 2 to > the power of 4 different thruth tables possible, which is indeed 16. > > Perhaps you have a link to all possible 16 thruth tables and their formal > names ? That would help ! http://en.wikipedia.org/wiki/Truth_table -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Fixing Python install on the Mac after running 'CleanMyMac'
In article <201505290347.t4t3lyjc006...@fido.openend.se>, Laura Creighton wrote: > webmas...@python.org just got some mail from some poor embarrased > soul who ran this program and broke their Python install. > > They are running Mac OSX 10.7.5 > > They are getting: > > Utility has encountered a fatal error, and will now terminate. A > Python runtime could not be located. You may need to install a > framework build of Python or edit the PyRuntimeLocations array in this > applications info.plist file. Then there are two oblong circles. One > says Open Console. The other says Terminate. > > So https://docs.python.org/2/using/mac.html says: > >The Apple-provided build of Python is installed in >/System/Library/Frameworks/Python.framework and /usr/bin/python, >respectively. You should never modify or delete these, as they are >Apple-controlled and are used by Apple- or third-party software. > > So, I assume this poor soul has done precisely that. > > What do I tell her to do now? It would be helpful to know what utility it is that is encountering the fatal error; that message is not familiar and I suspect it is coming from trying to run some third-party application. It may be that the application was depending on a third-party framework installation of Python (in /Library/Frameworks rather than the system Python in /System/Library/Frameworks), such as provided by the python.org OS X installers, but without knowing more information, like what particular version of Python is needed, it would only be speculation. Perhaps the best thing to do is to suggest the OP to participate directly here or an Apple users' forum like http://apple.stackexchange.com. -- Ned Deily, n...@acm.org -- https://mail.python.org/mailman/listinfo/python-list
Re: Creating a reliable sandboxed Python environment
Chris Angelico schrieb am 28.05.2015 um 20:51: > On Fri, May 29, 2015 at 4:41 AM, Stefan Behnel wrote: >> davidf...@gmail.com schrieb am 26.05.2015 um 04:24: >>> Has anyone on this list attempted to sandbox Python programs in a >>> serious fashion? I'd be interested to hear your approach. >> >> Not quite sandboxing Python, but I've seen people use my Lupa [1] library >> for this. They're writing all their code in Python, and then let users >> embed their own Lua code into it to script their API. The Lua runtime is >> apparently quite good at sandboxing, and it's really small, just some 600KB >> or so. Lupa then lets you easily control the access to your Python code at >> a whitelist level by intercepting all Python attribute lookups. >> >> It doesn't add much to your application to embed Lua (or even LuaJIT) in >> Python, and it gives users a nicely object oriented language to call and >> orchestrate your Python objects. > > Lua's a much weaker language than Python is, though. Can it handle > arbitrary-precision integers? Unicode? Dare I even ask, > arbitrary-precision rationals (fractions.Fraction)? All of those and way more, as long as you use it embedded in Python. > Security comes at a price, I guess. Sure, but features aren't the price here. Stefan -- https://mail.python.org/mailman/listinfo/python-list
