import os.path

    myPath = '/Users/t/web/perl-python/I_Love_You.html'
    (dirName, fileName) = os.path.split(myPath)
    (fileBaseName, fileExtension)=os.path.splitext(fileName)

    print dirName # /Users/t/web/perl-python
    print fileName # I_Love_You.html
    print fileBaseName # I_Love_You
    print fileExtension # .html

filePath = self.filePath
if not filePath:
    filePath = '../data'
fileName = QFileDialog.getOpenFileName (filePath, 'Arrays (*.inf; *.INF)', self, 'Select Array')
if not fileName: 
    return

import os
folder_size = os.path.getsize(filename)