Please explain what is going on with the or operator here in python
>>>sen='abcdef'
>>>'a' in sen
True
>>>'v' or 'z' in sen
'v'
>>>('v' or 'z') in sen
False
>>>('v' or 'a') in sen
False
>>>('a' or 'v') in sen
True
The first output obviously makes sense. From the second output, I do not follow what is going on!