Python If Condition with two conditions dependent on a tuple

I have only recently begun programming in Python (with previous Ruby experience). I am trying to set up an if condition with two conditions:

if not previous[1] and previous[0][0] == 5:
            prin开发者_JS百科t "hello world"

However, I keep getting this error:

<type 'exceptions.IndexError'>: tuple index out of range 

Print previous returns: ((5, 1, 9, 23),)

What am I doing wrong?

I am looking for something similar to they Ruby Syntax: unless previous[1]

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((5, 1, 9, 23),), then this is a length-1 tuple. It's only element--with index 0--is the tuple (5, 1, 9, 23). It doesn't have a second element to have the index 1, so that_tuple[1] raises IndexError.

What did you hope previous[1] would give you?

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There is only a single element in 'previous'. That is why you are getting an IndexError when you attempt to retrieve element 1.

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Your index error is coming from previous[1] - previous is 1-tuple ... you'd need previous[0] and previous[0][0].