在PyQt应用程序中嵌入IPython Qt控制台

Question

我想在我正在研究的PyQt应用程序中嵌入一个IPython qt控制台小部件.下面提供的代码(并改编自/sf/answers/685754401/)适用于IPython v0.12.但是,这在IPython v0.13中崩溃self.heartbeat.start()了RuntimeError: threads can only be started once.注释掉这一行会显示小部件,但不会响应用户输入.

有谁知道如何实现IPython v0.13的等效功能？

"""
Adapted from
https://stackoverflow.com/a/9796491/1332492
"""
import os
import atexit

from IPython.zmq.ipkernel import IPKernelApp
from IPython.lib.kernel import find_connection_file
from IPython.frontend.qt.kernelmanager import QtKernelManager
from IPython.frontend.qt.console.rich_ipython_widget import RichIPythonWidget
from IPython.config.application import catch_config_error
from PyQt4 import QtCore


class IPythonLocalKernelApp(IPKernelApp):
    DEFAULT_INSTANCE_ARGS = ['']

    @catch_config_error
    def initialize(self, argv=None):
        super(IPythonLocalKernelApp, self).initialize(argv)
        self.kernel.eventloop = self.loop_qt4_nonblocking

    def loop_qt4_nonblocking(self, kernel):
        """Non-blocking version of the ipython qt4 kernel loop"""
        kernel.timer = QtCore.QTimer()
        kernel.timer.timeout.connect(kernel.do_one_iteration)
        kernel.timer.start(1000*kernel._poll_interval)

    def start(self, argv=DEFAULT_INSTANCE_ARGS):
        """Starts IPython kernel app
        argv: arguments passed to kernel
        """
        self.initialize(argv)
        self.heartbeat.start()

        if self.poller is not None:
            self.poller.start()

        self.kernel.start()


class IPythonConsoleQtWidget(RichIPythonWidget):
    _connection_file = None

    def __init__(self, *args, **kw):
        RichIPythonWidget.__init__(self, *args, **kw)
        self._existing = True
        self._may_close = False
        self._confirm_exit = False

    def _init_kernel_manager(self):
        km = QtKernelManager(connection_file=self._connection_file, config=self.config)
        km.load_connection_file()
        km.start_channels(hb=self._heartbeat)
        self.kernel_manager = km
        atexit.register(self.kernel_manager.cleanup_connection_file)

    def connect_kernel(self, connection_file, heartbeat=False):
        self._heartbeat = heartbeat
        if os.path.exists(connection_file):
            self._connection_file = connection_file
        else:
            self._connection_file = find_connection_file(connection_file)

        self._init_kernel_manager()


def main(**kwargs):
    kernelapp = IPythonLocalKernelApp.instance()
    kernelapp.start()

    widget = IPythonConsoleQtWidget()
    widget.connect_kernel(connection_file=kernelapp.connection_file)
    widget.show()

    return widget

if __name__ == "__main__":
    from PyQt4.QtGui import QApplication
    app = QApplication([''])
    main()
    app.exec_()

跟踪v0.13

RuntimeError                              Traceback (most recent call last)
/Users/beaumont/terminal.py in <module>()
     80     from PyQt4.QtGui import QApplication
     81     app = QApplication([''])
---> 82     main()
        global main = <function main at 0x106d0c848>
     83     app.exec_()

/Users/beaumont/terminal.py in main(**kwargs={})
     69 def main(**kwargs):
     70     kernelapp = IPythonLocalKernelApp.instance()
---> 71     kernelapp.start()
        kernelapp.start = <bound method IPythonLocalKernelApp.start of     <__main__.IPythonLocalKernelApp object at 0x106d10590>>
     72 
     73     widget = IPythonConsoleQtWidget()

/Users/beaumont/terminal.py in start(self=<__main__.IPythonLocalKernelApp object>, argv=[''])
     33         """
     34         self.initialize(argv)
---> 35         self.heartbeat.start()
        self.heartbeat.start = <bound method Heartbeat.start of <Heartbeat(Thread-1, started daemon 4458577920)>>
     36 
     37         if self.poller is not None:

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.pyc in start(self=<Heartbeat(Thread-1, started daemon 4458577920)>)
    487             raise RuntimeError("thread.__init__() not called")
    488         if self.__started.is_set():
--> 489             raise RuntimeError("threads can only be started once")
        global RuntimeError = undefined
    490         if __debug__:
    491             self._note("%s.start(): starting thread", self)

RuntimeError: threads can only be started once

Answer 1

好吧,这段代码似乎可以解决问题(即它将一个非阻塞的ipython解释器放在一个Qt小部件中,可以嵌入到其他小部件中).传递的关键字将terminal_widget添加到窗口小部件的命名空间中

import atexit

from IPython.zmq.ipkernel import IPKernelApp
from IPython.lib.kernel import find_connection_file
from IPython.frontend.qt.kernelmanager import QtKernelManager
from IPython.frontend.qt.console.rich_ipython_widget import RichIPythonWidget
from IPython.utils.traitlets import TraitError
from PyQt4 import QtGui, QtCore

def event_loop(kernel):
    kernel.timer = QtCore.QTimer()
    kernel.timer.timeout.connect(kernel.do_one_iteration)
    kernel.timer.start(1000*kernel._poll_interval)

def default_kernel_app():
    app = IPKernelApp.instance()
    app.initialize(['python', '--pylab=qt'])
    app.kernel.eventloop = event_loop
    return app

def default_manager(kernel):
    connection_file = find_connection_file(kernel.connection_file)
    manager = QtKernelManager(connection_file=connection_file)
    manager.load_connection_file()
    manager.start_channels()
    atexit.register(manager.cleanup_connection_file)
    return manager

def console_widget(manager):
    try: # Ipython v0.13
        widget = RichIPythonWidget(gui_completion='droplist')
    except TraitError:  # IPython v0.12
        widget = RichIPythonWidget(gui_completion=True)
    widget.kernel_manager = manager
    return widget

def terminal_widget(**kwargs):
    kernel_app = default_kernel_app()
    manager = default_manager(kernel_app)
    widget = console_widget(manager)

    #update namespace                                                           
    kernel_app.shell.user_ns.update(kwargs)

    kernel_app.start()
    return widget

app = QtGui.QApplication([])
widget = terminal_widget(testing=123)
widget.show()
app.exec_()

Answer 2

@ChrisB接受的答案适用于IPython版本0.13,但它不适用于较新版本.在github上的IPython内核存储库的examples部分中,这是在v1.x +(目前使用4.0.1测试)中执行此操作的方法,其具有控制台和内核在同一进程中的功能.

这是一个基于官方示例的示例,它提供了一个可以轻松插入应用程序的便捷类.它设置为在Python 2.7上使用pyqt4和IPython 4.0.1:

(注意:您需要安装ipykernel和qtconsole软件包)

# Set the QT API to PyQt4
import os
os.environ['QT_API'] = 'pyqt'
import sip
sip.setapi("QString", 2)
sip.setapi("QVariant", 2)
from PyQt4.QtGui  import *
# Import the console machinery from ipython
from qtconsole.rich_ipython_widget import RichIPythonWidget
from qtconsole.inprocess import QtInProcessKernelManager
from IPython.lib import guisupport

class QIPythonWidget(RichIPythonWidget):
    """ Convenience class for a live IPython console widget. We can replace the standard banner using the customBanner argument"""
    def __init__(self,customBanner=None,*args,**kwargs):
        if not customBanner is None: self.banner=customBanner
        super(QIPythonWidget, self).__init__(*args,**kwargs)
        self.kernel_manager = kernel_manager = QtInProcessKernelManager()
        kernel_manager.start_kernel()
        kernel_manager.kernel.gui = 'qt4'
        self.kernel_client = kernel_client = self._kernel_manager.client()
        kernel_client.start_channels()

        def stop():
            kernel_client.stop_channels()
            kernel_manager.shutdown_kernel()
            guisupport.get_app_qt4().exit()            
        self.exit_requested.connect(stop)

    def pushVariables(self,variableDict):
        """ Given a dictionary containing name / value pairs, push those variables to the IPython console widget """
        self.kernel_manager.kernel.shell.push(variableDict)
    def clearTerminal(self):
        """ Clears the terminal """
        self._control.clear()    
    def printText(self,text):
        """ Prints some plain text to the console """
        self._append_plain_text(text)        
    def executeCommand(self,command):
        """ Execute a command in the frame of the console widget """
        self._execute(command,False)


class ExampleWidget(QWidget):
    """ Main GUI Widget including a button and IPython Console widget inside vertical layout """
    def __init__(self, parent=None):
        super(ExampleWidget, self).__init__(parent)
        layout = QVBoxLayout(self)
        self.button = QPushButton('Another widget')
        ipyConsole = QIPythonWidget(customBanner="Welcome to the embedded ipython console\n")
        layout.addWidget(self.button)
        layout.addWidget(ipyConsole)        
        # This allows the variable foo and method print_process_id to be accessed from the ipython console
        ipyConsole.pushVariables({"foo":43,"print_process_id":print_process_id})
        ipyConsole.printText("The variable 'foo' and the method 'print_process_id()' are available. Use the 'whos' command for information.")                           

def print_process_id():
    print 'Process ID is:', os.getpid()        

def main():
    app  = QApplication([])
    widget = ExampleWidget()
    widget.show()
    app.exec_()    

if __name__ == '__main__':
    main()

Answer 3

在PyQt5中工作的2016年更新:

from qtconsole.qt import QtGui
from qtconsole.rich_jupyter_widget import RichJupyterWidget
from qtconsole.inprocess import QtInProcessKernelManager


class ConsoleWidget(RichJupyterWidget):


    def __init__(self, customBanner=None, *args, **kwargs):
        super(ConsoleWidget, self).__init__(*args, **kwargs)

        if customBanner is not None:
            self.banner = customBanner

        self.font_size = 6
        self.kernel_manager = kernel_manager = QtInProcessKernelManager()
        kernel_manager.start_kernel(show_banner=False)
        kernel_manager.kernel.gui = 'qt'
        self.kernel_client = kernel_client = self._kernel_manager.client()
        kernel_client.start_channels()

        def stop():
            kernel_client.stop_channels()
            kernel_manager.shutdown_kernel()
            guisupport.get_app_qt().exit()

        self.exit_requested.connect(stop)

    def push_vars(self, variableDict):
        """
        Given a dictionary containing name / value pairs, push those variables
        to the Jupyter console widget
        """
        self.kernel_manager.kernel.shell.push(variableDict)

    def clear(self):
        """
        Clears the terminal
        """
        self._control.clear()

        # self.kernel_manager

    def print_text(self, text):
        """
        Prints some plain text to the console
        """
        self._append_plain_text(text)

    def execute_command(self, command):
        """
        Execute a command in the frame of the console widget
        """
        self._execute(command, False)


if __name__ == '__main__':
    app = QtGui.QApplication([])
    widget = ConsoleWidget()
    widget.show()
    app.exec_()