Using clipboard in PyQt

You can use the clipboard in your PyQt plugins by using the QApplication.clipboard().
First you import qthe QApplication from PyQt4.QtGui.

from PyQt4.QtGui import QApplication

Then you can create a variable, for example:

self.clip = QApplication.clipboard()

And then set some text to it:

self.clip.setText('some text')

Asking for User Input

In QGIS python (PyQGIS), the python comman raw_input() does not work as expected. And it will be not very practical to enter any input in Python Console.

One good alternative is to use "Qdialog". It is a module of PyQt (PyQt4.QtGui) library.
It can show a window asking for input, or asking to choose a file or folder.

We have to import it:

from PyQt4.QtGui import QFileDialog, QInputDialog, QMessageBox

QfileDialog - Window to select files or folders. It can be getOpenFileName - for opening files, getSaveFileName, for saving files, getExistingDirectory to select a folder. Example code for these types is shown below.

fileOpen = QFileDialog.getOpenFileName(None,'Select File:', 'c:/' , '.xls (*.xls)')

saveFileName = QtGui.QFileDialog.getSaveFileName(self, 'Dialog Title', '/path/to/default/directory', selectedFilter='*.txt')

folderSel = QFileDialog.getExistingDirectory(None,"Select Folder: ", 'c:/')

QInputDialog - customizable window. An example is shown below, showing a function that calls a customizable input window with defined width and height:

def windowSize(title, question, widthW, heightW):
    winD = QInputDialog(iface.mainWindow())
    winD.setInputMode(QInputDialog.TextInput)
    winD.setWindowTitle(title);
    winD.setLabelText(question)
    winD.resize(widthW,heightW)
    ok = winD.exec_()
    textInput = winD.textValue()
    return textInput

QMessageBox - It shows only a MessageBox With some information you want. Example:

QMessageBox.information(iface.mainWindow(), "Title", "Message")

Simple tutorial to Start with PyQt4

Good and simple.

http://zetcode.com/gui/pyqt4/