[         ]      any of the characters in here
 А-Я             any character from А and Я, inclusive
    а-я          any character between а and я, inclusive
       -         the character -   (this is ambiguous; it should only be at the very start or end of the class)
        \s       any whitespace character
           +     at least one of the preceding class of characters

[А-Яа-я-\s]+     at least one character between А and Я (uppercase or lowercase), a dash, or whitespace

[]在regex中被称为“类”，它的基本意思是“这里的任何字符都是有效的”。然后+意味着“前面的字符/类至少出现一次”。Python有一个正则表达式HowTo，你可能会发现通读它很有用。