Python中将系统输出显示在PyQt中

开发一个系统，需要将系统的输出显示在PyQt中，可以直接截获sys.stdout，也可以使用信号和槽来实现。

直接显示：

"""
Example usage:
import sys
sys.stdout = OutLog( edit, sys.stdout)
sys.stderr = OutLog( edit, sys.stderr, QtGui.QColor(255,0,0) )
"""
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):
        global aSigalOutLog

        if self.color:
            tc = self.edit.textColor()
            self.edit.setTextColor(self.color)

        self.edit.moveCursor(QtGui.QTextCursor.End)
        self.edit.insertPlainText(m)

        if self.color:
            self.edit.setTextColor(tc)

        if self.out:
            self.out.write(m)

这种方法在多线程处理时可能有点问题，下面可以使用信号和槽来实现：

#encoding=gb2312

import sys
from PyQt4 import QtCore, QtGui
from PyQt4.QtCore import *
from PyMailServerMain import Ui_MainWindow


#信用信号和槽来处理日志
class SigalOutLogSender(QObject):
    def SendMsg(self, m):
        self.emit(SIGNAL('DisplayLog(QString)'),m)

aSigalOutLog=SigalOutLogSender()

class OutLog:
    def __init__(self):
        pass

    def write(self, m):
        global aSigalOutLog
        aSigalOutLog.SendMsg(u'%s' % m)


class StartQt4(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

        QtCore.QObject.connect(self.ui.btnSendMail,QtCore.SIGNAL("clicked()"), self.ProcessSend, 1)

        #捕捉系统输出
        sys.stdout = OutLog()
        sys.stderr = OutLog()

        #使用信号和槽来处理日志
        global aSigalOutLog
        QtCore.QObject.connect(aSigalOutLog,QtCore.SIGNAL("DisplayLog(QString)"), self.DisplayLog, 1)
    def ProcessSend(self):
        #使用信号和槽来处理日志
        global aSigalOutLog
        print u'测试标准输出'

    def DisplayLog(self,log):
        self.ui.memLog.moveCursor(QtGui.QTextCursor.End)
        self.ui.memLog.insertPlainText(log)


if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    myapp = StartQt4()
    myapp.show()
    sys.exit(app.exec_())