only_roman_chars(
    '\u03b5\u03bb\u03bb\u03b7\u03bd\u03b9\u03ba\u03ac means greek')
only_roman_chars('frapp\xe9')
only_roman_chars('h\xf4tel l\u0153we')
only_roman_chars('123 \xe5ngstrom \xf0 \xe1\xdf')
only_roman_chars('russian: \u0433\u0430\u0433\u0430')
How can I check if a Python unicode string contains non-Western letters?