QTextEdit 小部件中的重复标准输出、标准错误 [英] Duplicate stdout, stderr in QTextEdit widget
问题描述
我的 PySide 程序已经有几天了.我不认为这个问题非常困难，因为那里有答案.我的问题是它们似乎都不适合我.
I've been having difficulty with my PySide program for a few days now. I don't think the problem is incredibly difficult because there are answer out there. Problem I have is none of them seem to work for me.
我想在 PySide 程序运行时收听"文件对象 stdout 和 stderr 并将内容输出到 QText Edit 小部件.现在，我已经意识到这里之前已经问过这个问题(或类似的问题)，但就像我说的那样，由于某种原因无法让它为我工作，而且大多数其他解决方案都基于我可以解决的问题没有开始工作，所以最后几天对我来说非常令人沮丧.这个解决方案 (OutLog) 包含在我下面的代码片段中，以防万一你们中的一个人可以看到我的拙劣实现.
I want to 'listen' to the file objects stdout and stderr and output the contents to QText Edit widget while my PySide program is running. Now, I already realise this question (or something similar) has been asked before on here but like I said, can't get it to work for me for some reason and most other solutions out there are based on the one that I can't get working, so a very frustrating last few days for me. This solution (OutLog), is included in my code snippet below, just in case one of you guys can see a botched implementation on my part.
要记住的事情:
1 我在 Windows 7 上执行此操作(duuuh、da、da、duh)
1 I'm doing this on Windows 7(duuuh, da, da, duh)
2 我正在使用 Eclipse 并从 IDE 内部运行它(duh、da、da、duh、DUUUUH:如果这些建议适用于命令行或 IDE，那将非常方便)
2 I'm using eclipse and running it from inside the IDE(duh, da, da, duh, DUUUUH: It would be really handy if the suggestions worked with either commandline or an IDE)
3 我真的只想在程序运行时将 stdout 和 stderr 的输出复制到小部件.对于逐行发生这种情况将是一个梦想，但即使这一切都在循环结束时作为一个块出现或其他东西，那也很棒.
3 I really just want to duplicate the output of stdout and stderr to the widget while the program runs. For this to happen line-by-line would be a dream but even if it all comes out as a chunk at the end of a loop or something, that would be fab.
4 哦，还有关于 OutLog，有人能告诉我，如果在 init 中将 self.out 设置为None"，这个类实际上可以工作吗?我的意思是，self.out 总是一个 NoneType 对象，对吧???
4 Oh, and also regarding OutLog, could somebody tell me how, if self.out is set to 'None' in the init, this class can actually work? I mean, self.out is always a NoneType object, right???
任何帮助将不胜感激，即使它只是指向我可以找到更多信息的地方.我一直在尝试构建自己的解决方案(我在这方面有点虐待狂)，但我发现很难找到有关这些对象如何工作的相关信息.
Any help would be appreciated, even if it's just pointers to where I could find more information. I've been trying to build my own solution (I'm a bit of a sadist that way) but I've found it hard to find relevant info on how these objects work to do that.
无论如何，抱怨一下.这是我的代码:
Anyway, whine over. Here's my code:
#!/usr/bin/env python
import sys
import logging
import system_utilities
log = logging.getLogger()
log.setLevel("DEBUG")
log.addHandler(system_utilities.SystemLogger())
import matplotlib
matplotlib.use("Qt4Agg")
matplotlib.rcParams["backend.qt4"] = "PySide"
import subprocess
import plot_widget
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from PySide import QtCore, QtGui
class MainWindow(QtGui.QMainWindow):
"""This is the main window class and displays the primary UI when launched.
Inherits from QMainWindow.
"""
def __init__(self):
"""Init function.
"""
super(MainWindow, self).__init__()
self.x = None
self.y = None
self.data_plot = None
self.plot_layout = None
self.terminal = None
self.setup_plot()
self.setup_interface()
def setup_plot(self):
"""Member function to setup the graph window in the main UI.
"""
#Create a PlotWidget object
self.data_plot = plot_widget.PlotWidget()
#Create a BoxLayout element to hold PlotWidget
self.plot_layout = QtGui.QVBoxLayout()
self.plot_layout.addWidget(self.data_plot)
def setup_interface(self):
"""Member function to instantiate and build the composite elements of the
UI."""
#Main widget houses layout elements (Layout cannot be placed directly in a QMainWindow).
central_widget = QtGui.QWidget()
test_splitter = QtGui.QSplitter(QtCore.Qt.Vertical)
button_splitter = QtGui.QSplitter(QtCore.Qt.Horizontal)
#UI BoxLayout elements
central_layout = QtGui.QVBoxLayout()
#button_layout = QtGui.QHBoxLayout()
#UI PushButton elements
exit_button = QtGui.QPushButton("Close")
run_button = QtGui.QPushButton("Run...")
#UI Text output
self.editor = QtGui.QTextEdit()
self.editor.setReadOnly(True)
self.terminal = QtGui.QTextBrowser()
self.terminal.setReadOnly(True)
#UI PushButton signals
run_button.clicked.connect(self.run_c_program)
run_button.clicked.connect(self.data_plot.redraw_plot)
exit_button.clicked.connect(QtCore.QCoreApplication.instance().quit)
#Build the UI from composite elements
central_layout.addLayout(self.plot_layout)
central_layout.addWidget(self.editor)
button_splitter.addWidget(run_button)
button_splitter.addWidget(exit_button)
test_splitter.addWidget(button_splitter)
test_splitter.addWidget(self.terminal)
test_splitter.setCollapsible(1, True)
central_layout.addWidget(test_splitter)
central_widget.setLayout(central_layout)
self.setCentralWidget(central_widget)
self.show()
class OutLog:
def __init__(self, edit, out=None, color=None):
"""(edit, out=None, color=None) -> can write stdout, stderr to a
QTextEdit.
edit = QTextEdit
out = alternate stream ( can be the original sys.stdout )
color = alternate color (i.e. color stderr a different color)
"""
self.edit = edit
self.out = None
self.color = color
def write(self, m):
if self.color:
tc = self.edit.textColor()
self.edit.setTextColor(self.color)
self.edit.moveCursor(QtGui.QTextCursor.End)
log.debug("this is m {}".format(m))
self.edit.insertPlainText( m )
if self.color:
self.edit.setTextColor(tc)
if self.out:
self.out.write(m)
def main():
app = QtGui.QApplication(sys.argv)
log.debug("Window starting.")
window = MainWindow()
sys.stdout = OutLog(window.terminal, sys.stdout)
sys.stderr = OutLog(window.terminal, sys.stderr, QtGui.QColor(255,0,0))
window.show()
sys.exit(app.exec_())
log.info("System shutdown.")
if __name__ == '__main__':
main()
帮帮我欧比旺..."
在此先感谢大家(和 gals :-))
Thanks in advance guys (and gals :-))
推荐答案
看来你需要做的就是用一个覆盖 sys.stderr 和 sys.stdout每当写入输出时都会发出信号的包装器对象.
It seems that all you need to do is override sys.stderr and sys.stdout with a wrapper object that emits a signal whenever output is written.
下面是一个演示脚本，它应该或多或少地满足您的需求.请注意，包装类不会从 sys.__stdout__/sys.__stderr__ 恢复 sys.stdout/sys.stderr，因为后者的对象可能与原来被替换了.
Below is a demo script that should do more or less what you want. Note that the wrapper class does not restore sys.stdout/sys.stderr from sys.__stdout__/sys.__stderr__, because the latter objects may not be same as the ones that were orignally replaced.
import sys
from PyQt4 import QtGui, QtCore
class OutputWrapper(QtCore.QObject):
outputWritten = QtCore.pyqtSignal(object, object)
def __init__(self, parent, stdout=True):
QtCore.QObject.__init__(self, parent)
if stdout:
self._stream = sys.stdout
sys.stdout = self
else:
self._stream = sys.stderr
sys.stderr = self
self._stdout = stdout
def write(self, text):
self._stream.write(text)
self.outputWritten.emit(text, self._stdout)
def __getattr__(self, name):
return getattr(self._stream, name)
def __del__(self):
try:
if self._stdout:
sys.stdout = self._stream
else:
sys.stderr = self._stream
except AttributeError:
pass
class Window(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
widget = QtGui.QWidget(self)
layout = QtGui.QVBoxLayout(widget)
self.setCentralWidget(widget)
self.terminal = QtGui.QTextBrowser(self)
self._err_color = QtCore.Qt.red
self.button = QtGui.QPushButton('Test', self)
self.button.clicked.connect(self.handleButton)
layout.addWidget(self.terminal)
layout.addWidget(self.button)
stdout = OutputWrapper(self, True)
stdout.outputWritten.connect(self.handleOutput)
stderr = OutputWrapper(self, False)
stderr.outputWritten.connect(self.handleOutput)
def handleOutput(self, text, stdout):
color = self.terminal.textColor()
self.terminal.setTextColor(color if stdout else self._err_color)
self.terminal.moveCursor(QtGui.QTextCursor.End)
self.terminal.insertPlainText(text)
self.terminal.setTextColor(color)
def handleButton(self):
if QtCore.QTime.currentTime().second() % 2:
print('Printing to stdout...')
else:
sys.stderr.write('Printing to stderr...\n')
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 300, 200)
window.show()
sys.exit(app.exec_())
注意:
应尽早创建OutputWrapper的实例，以确保其他需要sys.stdout/sys.stderr的模块(如logging模块)在必要时使用包装版本.
Instances of the OutputWrapper should be created as early as possible, so as to ensure that other modules that need sys.stdout/sys.stderr (such as the logging module) use the wrapped versions wherever necessary.
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