运行PyQt4示例代码没有任何反应

Question

I am trying to run some example code using PyQt4. I am trying to run it from Notepad++ and also from the Enthought Canopy environment. The example code is shown below in its entirety. From within npp, I am using the plugin nppExec with python -i "$(FULL_CURRENT_PATH)" as the command. (i also tried it without interactive -i)

import sys
from PyQt4 import QtGui


def main():

    app = QtGui.QApplication(sys.argv)

    w = QtGui.QWidget()
    w.resize(250, 150)
    w.move(300, 300)
    w.setWindowTitle('Simple')
    w.show()

    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

When I run it from within npp, The internal console seems to freeze up (no errors) and is recoverable with ctrl-c

When I run it from within Canopy, I get the following error message

%run "c:\users\brian\appdata\local\temp\tmpfe9mmh.py"
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
C:\Users\Brian\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.0.0.1160.win-x86\lib\site-packages\IPython\utils\py3compat.pyc in execfile(fname, glob, loc)
    174             else:
    175                 filename = fname
--> 176             exec compile(scripttext, filename, 'exec') in glob, loc
    177     else:
    178         def execfile(fname, *where):

c:\users\brian\appdata\local\temp\tmpfe9mmh.py in <module>()
     20 
     21 import sys
---> 22 from PyQt4 import QtGui
     23 
     24 

C:\Users\Brian\AppData\Local\Enthought\Canopy32\App\appdata\canopy-1.0.0.1160.win-x86\lib\site-packages\IPython\external\qt_loaders.pyc in load_module(self, mod_name)
     43     Importing %s disabled by IPython, which has
     44     already imported an Incompatible QT Binding: %s
---> 45     """ % (mod_name, loaded_api()))
     46 
     47 ID = ImportDenier()

ImportError: 
    Importing PyQt4 disabled by IPython, which has
    already imported an Incompatible QT Binding: pyside

I am pretty confused as to why Canopy places its items in a seemingly strange place (C:\\Users\\Brian\\AppData\\Local\\Enthought\\Canopy32), rather than the simple C:/python27

I am running python 2.7 32 bit, Canopy Version: 1.0.0.1160 32 bit, Win7 64 bit

Answer 1

It looks like pyside (an alternative python binding for Qt) is somehow being automatically imported when python is run on your machine. import both pyside and pyqt is causing some sort of clash that is causing your problems.

I wonder.. do you have a module named sys.py in your path that is using pyside? You are importing sys which is a built-in module, but if you have a file named sys.py in your path, that will be imported instead. If this is the case, then you can run the script:

import sys

print sys.__file__

to find where the file is. If the sys module being imported is actually the built-in module, sys will not have a __file__ attribute and an exception will be raised.

By the way, I tried your example code on my machine and it ran without any issues.

Answer 2

In NppExec, use the command

CMD /C python -u "$(FULL_CURRENT_PATH)"

instead of

python "$(FULL_CURRENT_PATH)"