Should return a list of files that end in a specified extension.

findfile.py

def find_file_by_type(file_extension, directory=''):
    if directory == '':
        root = Tkinter.Tk()
        directory = tkFileDialog.askdirectory(parent = root, initialdir = "/", title = 'Please Select a Directory')
        root.withdraw()
        os.chdir(directory)
    targetfiles = []
    for root, dirs, filenames in os.walk(directory):
        for name in filenames:
            if os.path.splitext(name)[1] == file_extension:
                targetfiles.append(os.path.join(root,name))
    if len(targetfiles) > 0:
        print('{} {} files found'.format(str(len(targetfiles)),file_extension))
        return targetfiles
    else:
        print('No {} file found'.format(file_extension))
        return targetfiles