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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 is_allowed(self, filepath, excludes=[]):
 """ Check from exclude patterns if a relative filepath is allowed Args: filepath (str):
 A relative file path. (exclude patterns are allways based from the source directory). Keyword Arguments: excludes (list):
 A list of excluding (glob) patterns. If filepath matchs one of patterns, filepath is not allowed. Raises: boussole.exception.FinderException: If given filepath is absolute. Returns: str: Filepath with new extension. """

        if os.path.isabs(filepath):
            raise FinderException("'Finder.is_allowed()' only accept relative"
                                  " filepath")

        if excludes:
            for pattern in excludes:
                if fnmatch.fnmatch(filepath, pattern):
                    return False
        return True