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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 _get_content_type(self, filename):
 """ gets the content type of a file """

        mntype = mimetypes.guess_type(filename)[0]
        filename, fileExtension = os.path.splitext(filename)
        if mntype is None and\
            fileExtension.lower() == ".csv":
            mntype = "text/csv"
        elif mntype is None and \
            fileExtension.lower() == ".sd":
            mntype = "File/sd"
        elif mntype is None:
            #mntype = 'application/octet-stream'
            mntype= "File/%s" % fileExtension.replace('.', '')
        return mntype