[Tutor] __getitem__

[Alan Gauld]

> Sorry!
> 
> X = stepper()
> X.data = "Spam"

Aha! The fog in my brain clears.

>> > >>> class stepper:
>> >...     def __getitem__(self, i):
>> >...         return self.data[i]
>> >...
>> > >>> 'p' in X
>> >True
>> >
>> >What does 'in' have to do with indexing?

To find out if 'p' is in X Python has to step through the data in X.
I'm not sure that your getitem is being called, it may just be a string 
search operation. But I suspect it may assume the data is an iterator
and repeatedly call next() till it gets a match or runs out of data. 
In that case getitem may well get called. a simple print statement 
in getitem will find out...

Alan G.