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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 pseudos_with_symbols(self, symbols):
 """ Return the pseudos with the given chemical symbols. Raises: ValueError if one of the symbols is not found or multiple occurences are present. """

        pseudos = self.select_symbols(symbols, ret_list=True)
        found_symbols = [p.symbol for p in pseudos]
        duplicated_elements = [s for s, o in collections.Counter(found_symbols).items() if o > 1]

        if duplicated_elements:
            raise ValueError("Found multiple occurrences of symbol(s) %s" % ', '.join(duplicated_elements))
        missing_symbols = [s for s in symbols if s not in found_symbols]

        if missing_symbols:
            raise ValueError("Missing data for symbol(s) %s" % ', '.join(missing_symbols))

        return pseudos