在Python中将元组与字符串进行比较

Question

I have spent couple hours trying to figure out how tuples and strings are compared in Python. I have a theory, but just wanted to check if I was correct.

Given the code:

 if('michael' is 'hello',):
     print "true"

why does this always return true?

Answer 1

'michael' is 'hello' is obviously False, so the result is if (False,): . A tuple doesn't care what's inside; it has a boolean value of True if there is just at least one something in there, and False if not. Even though the only item there is False, it returns True because at least there's something. If you want to see if every item is True, use if all(('michael' is 'hello',)):