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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def start_file(filename):

 """
 Generalized os.startfile for all platforms supported by Qt
 
 This function is simply wrapping QDesktopServices.openUrl
 
 Returns True if successfull, otherwise returns False.
 """

    from qtpy.QtCore import QUrl
    from qtpy.QtGui import QDesktopServices

    # We need to use setUrl instead of setPath because this is the only
    # cross-platform way to open external files. setPath fails completely on
    # Mac and doesn't open non-ascii files on Linux.
    # Fixes Issue 740
    url = QUrl()
    url.setUrl(filename)
    return QDesktopServices.openUrl(url)