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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 prepare_file(filename):
 """Truncate the file and return the filename."""

    directory = os.path.join(utils.get_project_root(), "analyzation/")
    if not os.path.exists(directory):
        os.makedirs(directory)
    workfilename = os.path.join(directory, filename)
    open(workfilename, 'w').close()  # Truncate the file
    return workfilename