I've created a tool in Maya that takes values from currently selected objects, does some modifications to them and gives them back.I also have a simple gui window(made in QtDesigner if it makes sense),which has a QSlider and I pass values by dragging this slider. So, everything was working fine and I thought that it's completely ready for using but some problems with undo appeared. So, below in the init method I do this
super(winMain, self).__init__()
loader = QtUiTools.QUiLoader()
self.ui = loader.load(ui_path, self)
self.slider_released = self.ui.slider.sliderReleased
I have more code written in here it's just not connected to this. Below is the actionCaller() function where I call the action() function(this just does some math and generates values that should be passed to objects).
def actionCaller(self, some_value):
cmds.undoInfo(openChunk=True, infinity=True)
while not self.slider_released:
continue
else:
self.action(some_value)
cmds.undoInfo(closeChunk=True)
So I want to pass sliders value(some_value) only when it's released and therefor I added cmds.undoInfo() method for undoing the whole process as a one undo. Everything works fine while I use my program, only when I try to undo actions I've done before executing my code Maya gives this error:
// Error: line 1: Undo is temporarily unavailable. Try exiting the current tool.
I think that maya somehow gets in the while loop that I wrote above and undo queue becomes unavailable. Maybe I'm wrong idk. Can someone please tell me what the problem could be in here?
Thanks in advance :)
Comments section is not comfortable for posting code so I'm doing it here.
#musicamante using sliderReleased as a condition was actually a bad idea, so doing what you suggested helped. I modified the code a little bit and now it looks like this and everything works as expected:
self.ui.slider.sliderReleased.connect(self.actionCaller)
and
def actionCaller(self, slider_value):
cmds.undoInfo(openChunk=True, infinity=True)
try:
while not True:
continue
else:
self.action(slider_value)
finally:
cmds.undoInfo(closeChunk=True)
Thanks for your help:)
Related
I am writing a game, similar to mastermind, and I want a choice bewteen an easy or hard version. I'm not sure how to do this as I need the question before the actual game starts but then there's an error because the function is being called to run before it has been assigned.
def difficulty():
difficulty = input("would you like to the easy or hard version?")
if difficulty == ("easy"):
easy()
elif difficulty == ("hard"):
hard()
difficulty()
This is the start then after is the function with the harder game code then the easier game code. I am trying to run the easy if they request easy and vice versa but the easy () and hard() don't run the code as it isn't assigned yet. I think this is because python reads the code from top to bottom and stops when it finds an error but not sure.
I have never used this before so I apologise if things are unclear or I have done some things wrong.
I am also relatively new to python.
If anybody could help me I would greatly apprectiate it.
Python is quite smart when it comes to identifying functions inside a module. For instance you could do this:
def x():
y()
def y():
print("Y")
x()
and it would execute correctly.
You are right about the execution of a code block that happens from top to bottom, as well as the definitions of those functions will also be constructed top to button, but executed afterwards.
I see some issues in your code.
you do difficulty = input("would you like to the easy or hard version?") but at the same time you have a function called def difficulty. There is a conflict there, try to rename that variable.
you don't need to do ("easy"), it's overkill, you can compare directly to "easy".
I have started network programming using Python and am working on a basic peer-to-peer chat client-server application. I got it working for console, but am facing problem while developing a GUI.
This is the code for my client script. It is sending data to the server but is unable to receive /display the data sent from server, I am at a loss. Please show the error in my code and the solution.
from socket import *
from tkinter import *
host="127.0.0.1"
port=1420
buffer=1024
server=(host,port)
clientsock=socket(AF_INET,SOCK_STREAM)
clientsock.connect(server)
class ipbcc(Frame):
def __init__(self,master):
Frame.__init__(self,master)
self.grid()
self.create()
self.connect()
def write(self,event):
msg=self.e.get()
clientsock.send(msg.encode())
def create(self):
self.pic=PhotoImage(file="logo.gif")
self.label=Label(self,image=self.pic)
self.label.grid(column=0)
self.wall=Text(self,width=70,height=20,wrap=WORD)
self.wall.grid(row = 0, column = 1, columnspan = 2, sticky = W)
self.e=Entry(self,width=50)
self.e.grid(row = 1, column = 1, sticky = W)
self.e.bind('<Return>',self.write)
def add(self,data):
self.wall.insert(END,data)
def connect(self):
def xloop():
while 1:
data=clientsock.recv(buffer).decode()
print(data)
self.add(data)
root=Tk()
root.title("IPBCC v0.1")
app=ipbcc(root)
root.mainloop()
PS: Python Version 3.3 and there is no problem in the server script.
Your connect function defines a function called xloop, but it doesn't call that function, or return it, or store it somewhere for anyone else to call it. You need to call that function for it to do anything.
Of course if you just call it directly inline, it will run forever, meaning you never get back to the event loop, and the UI freezes up and stops responding to the user.
There are two options for this: threading, or polling.
The obvious way to do this is with a background thread. The basic idea is very simple:
def connect(self):
def xloop():
while 1:
data=clientsock.recv(buffer).decode()
print(data)
self.add(data)
self.t = threading.Thread(target=xloop)
self.t.start()
However, there are two problems with this.
First, there's no way to stop the background thread. When you try to exit the program, it will wait for the background thread to stop—which means it will wait forever.
There's an easy solution to that one: if you make it a "daemon thread", it will be summarily killed when the main program exits. This is obviously no good for threads that are doing work that could be corrupted if interrupted in the middle, but in your case that doesn't seem to be a problem. So, just change one line:
self.t = threading.Thread(target=xloop, daemon=True)
Second, that self.add method needs to modify a Tkinter widget. You can't do that from a background thread. Depending on your platform, it may fail silently, raise an exception, or even crash—or, worse, it may work 99% of the time and fail 1%.
So, you need some way to send a message to the main thread, asking it to do the widget modification for you. This is a bit complicated, but Tkinter and Threads explains how to do it.
Alternatively, you could use mtTkinter, which intercepts Tkinter calls in background threads and passes them to the main thread automatically, so you don't have to worry about it.
The other option is to change the blocking xloop function into a nonblocking function that polls for data. The problem is that you want to wait on Tkinter GUI events, but you also want to wait on the socket.
If you could integrate the socket into the main event loop, that would be easy: a new message coming in would be handled just like any other event. Some of the more powerful GUI frameworks like Qt give you ways to do this, but Tkinter does not. A reactor framework like Twisted can tie itself into Tkinter and add it for you (or at least fake nicely). But if you want to stick with your basic design, you have to do it yourself.
So, there are two options:
Give Tkinter full control. Ask it to call your function every, say, 1/20th of a second, and in the function do a non-blocking check. Or maybe loop around non-blocking checks until there's nothing left to read.
Give the socket control. Ask Tkinter to call your function every time it gets a chance, and block for 1/20th of a second checking for data before returning to Tkinter.
Of course 1/20th of a second may not be the right length—for many applications, no answer is really correct. Anyway, here's a simple example:
def poll_socket(self):
r, w, x = select.select([clientsock], [], [], 0)
if r:
data=clientsock.recv(buffer).decode()
print(data)
self.add(data)
self.after(50, self.poll_socket)
def connect(self):
self.after(50, self.poll_socket)
You define xloop, however you never actually call it as far as I can see.
I would suggest you look into using threads - the threading module in the standard library would be one way to go. Then, in your code you will be able to create a thread running the xloop function, without stopping the rest of your code. Alternatively, you could remove the loop from xloop (or indeed just put the code in the function into the connect function) and call it periodically, using widget.after(milliseconds, a_function)
I'd also like to mention that from amodule import * is considered bad practice (although tkinter is one of the exceptions to this rule).
It might help to follow the flow. The "app=ipbcc(root)" step would call "self.connect()" and that has a "def xloop():" that has the step "data=clientsock.recv". But, then somebody needs to invoke xloop(). Who does that? Btw, why do have a function inside a method?
Also, I don't see anybody invoking the "clientsock.send(msg.encode())" via the write() method. I am not familiar with the Tinker part (and what the mainloop() does), so can you please check if there are callers to send() and the recv() call.
I was wondering if anyone had any good solutions to the pickling error I am having at the moment. I am trying to set my code up to open several different processes in parallel, each with a fitting process to be display on a matplotlib canvas in real time. Within my main application, I have a button which activates this function:
def process_data(self):
process_list = []
for tab in self.tab_list:
process_list.append(mp.Process(target=process_and_fit, args=(tab,)))
process_list[-1].start()
process_list[-1].join()
return
As you may notice, a 'tab' (PyQt4.QtGui.QTabWidget object) is passed to the function process_and_fit, which I have noticed is not able to be pickled readily (link here) .
However, I am not certain how to change the code to get rid of the frame being passed since it needs to be called in the process_and_fit function indirectly. By indirectly I mean something like this: (psuedo code again)
def process_and_fit(tab): # this just sets up and starts the fitting process
result = lmfit.Minimizer(residual, parameters, fcn_args=(tab,))
result.prepare_fit()
result.leastsq()
def residual(params, tab):
residual_array = Y - model
tab.refreshFigure()
return residual_array
class tab(QtGui.QTabWidget):
def __init__(self, parent, spectra):
# stuff to initialize the tab widget and hold all of the matplotlib lines and canvases
# This just refreshes the GUI stuff everytime that the parameters are fit in the least squares method
def refreshFigure(self):
self.line.set_data(self.spectra.X, self.spectra.model)
self.plot.draw_artist(self.line)
self.plot.figure.canvas.blit(self.plot.bbox)
Does anyone know how to get around this pickling error since the tab associated with a process should have only one set of data associated with it? I looked at Steven Bethard's approach but I really didn't understand where to put the code or how to utilize it. (I am a chemical engineer, not a computer scientist so there's a lot that I don't understand)
Any help is greatly appreciated.
EDIT: I added the links in that I forgot about, as requested.
The main issue is that you can't make UI changes from a separate process from the main UI thread (the one that all of your Qt calls are in). You need to use a mp.Pipe or mp.Queue to communicate back to the main process.
def process_data(self):
for tab in self.tab_list:
consumer, producer = mp.Pipe()
process_list.append(mp.Process(target=process_and_fit, args=(producer,)))
process_list[-1].start()
while (true):
message = consumer.recv() # blocks
if message == 'done':
break
# tab.spectra.X, tab.spectra.model = message
tab.refreshFigure()
process_list[-1].join()
return
def process_and_fit(pipe_conn):
...
pipe_conn.send('done')
def residual(params, pipe_conn):
residual_array = Y - model
pipe_conn.send('refresh') # or replace 'refresh' with (X, model)
return residual_array
One more thing to note: blocking for the consumer.recv() will probably hang the GUI thread. There are plenty of resources to mitigate this, the question "subprocess Popen blocking PyQt GUI" will help, since you should probably switch to QThreads. (Qthread: PySide, PyQt)
The advantage of using QThreads instead of Python threads is that with QThreads, since you're already in Qt's main event loop, you can have asynchronous (non-blocking) callbacks to update the UI.
I am collecting usage stats for my applications which include how much each session lasts. However, I can't seem to be able to save this information because None Of the signals I tried yet actually succeeds to call my report_session function.
This are the signals I have already tried:
lastWindowClosed()
aboutToQuit()
destroyed()
Either these signals never get emitted or the application does not live long enough after that to run anything else. Here is my main:
app = QtGui.QApplication(sys.argv)
ui = MainWindow()
ui.app = app
QtCore.QObject.connect(ui, QtCore.SIGNAL("destroyed()"), ui.report_session)
ui.show()
logger.info('Started!')
splash.finish(ui)
sys.exit(app.exec_())
The method that Mark Byers posted will run after the main widget has been closed, meaning that its controls will no longer be available.
If you need to work with any values from controls on your form, you will want to capture the close event and do your work there:
class MainWidget(QtGui.QWidget):
#...
def closeEvent(self, event):
print "closing PyQtTest"
self.SaveSettings()
# report_session()
Also, see the Message Box example in the ZetCode tutorial First programs in PyQt4 toolkit (near the end of the page). This shows how to accept or cancel the close request.
Put the code between app.exec_ and sys.exit:
ret = app.exec_()
# Your code that must run when the application closes goes here
sys.exit(ret)
To ensure that a Python function gets called at process termination, in general (with or without Qt involved;-), you can use the atexit module of the standard Python library:
import atexit
def whatever(): ...
atexit.register(whatever)
Out of prudence I would recommend against using a bound method instead of a function for this purpose -- it "should" work, but the destruction-phase of a process is always somewhat delicate, and the simpler you keep it, the better.
atexit won't trigger for a sufficiently-hard crash of a process, of course (e.g., if the process is killed with a kill -9, then by definition it's not given a chance to run any termination code) -- the OS sees to that;-). If you need to handle any crash no matter how hard you must do so from a separate "watchdog" process, a substantially subtler issue.
Found this answer which involves overloading closeEvent().
it worked perfectly for me.
I defined an handler for EVT_IDLE that does a certain background task for me. (That task is to take completed work from a few processes and integrate it into some object, making a visible change in the GUI.)
The problem is that when the user is not moving the mouse or doing anything, EVT_IDLE doesn't get called more than once. I would like this handler to be working all the time. So I tried calling event.RequestMore() at the end of the handler. Works, but now it takes a whole lot of CPU. (I'm guessing it's just looping excessively on that task.)
I'm willing to limit the number of times the task will be carried out per second; How do I do that?
Or do you have another solution in mind?
Something like this (executes at most every second):
...
def On_Idle(self, event):
if not self.queued_batch:
wx.CallLater(1000, self.Do_Batch)
self.queued_batch = True
def Do_Batch(self):
# <- insert your stuff here
self.queued_batch = False
...
Oh, and don't forget to set self.queued_batch to False in the constructor and maybe call event.RequestMore() in some way in On_Idle.
This sounds like a use case for wxTimerEvent instead of wxIdleEvent. When there is processing to do call wxTimerEvent.Start(). When there isn't any to do, call wxTimerEvent.Stop() and call your methods to do processing from EVT_TIMER.
(note: i use from wxWidghets for C++ and am not familiar with wxPython but I assume they have a similar API)