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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 find(identifier):
 """ Find and return a format by name, acronym or extension. :param identifier: A string describing the format. """

    for format in FORMATS:
        if identifier in [format.name, format.acronym, format.extension]:
            return format

    raise UnknownFormat('No format found with name, acronym or extension "%s"' % identifier)