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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 element_data_from_sym(sym):
    '''Obtain elemental data given an elemental symbol

    The given symbol is not case sensitive

    An exception is thrown if the symbol is not found
    '''

    sym_lower = sym.lower()
    if sym_lower not in _element_sym_map:
        raise KeyError('No element data for symbol \'{}\''.format(sym))
    return _element_sym_map[sym_lower]