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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 from_filename(file_name):
 """ Look up the BioPython file type corresponding to an input file name. """

    base, extension = os.path.splitext(file_name)
    if extension in COMPRESS_EXT:
        # Compressed file
        extension = os.path.splitext(base)[1]
    return from_extension(extension)