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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 abslistdir(directory):
 """ returns a list of absolute filepaths for all files found in the given directory. """

    abs_dir = os.path.abspath(directory)
    filenames = os.listdir(abs_dir)
    return [os.path.join(abs_dir, filename) for filename in filenames]