If the items in a tuple are mutable, then you’ll be able to change them even if the tuple itself is immutable. In other words, the immutability of Python tuples refers to the references it directly holds. It doesn’t extend to the referenced objects themselves. In general, putting mutab...
>>>a = {'thank','you','mike','please','help','me'}>>>b = {'no','thank','it','is','me'}>>>a | b {'please','you','mike','is','it','help','thank','no','me'}# union()参数可以为空,则返回集合的所有元素>>>a.union(b) {'please','you','mike','is','it',...