[Python] Errors while using strip and remove on a variable.

On a list, the "remove" method does not create and return a new list --
instead it removes the element from the list in place. In your code,
you "print a" and "print c", but you should have done "print b", where
you will find the result you expect.

Gary Herron

The remove method of a list modifies the list in place and doesn't
return anything (Therefore, it returns None because every
function/method in Python has to return something). There's no need to
assign the result to a variable.

As others have stated, the issue is that b.remove('oe') doesn't return b
or a copy of b, but directly modifies b instead.

I'll add that you will find that this behavior is consistent throughout
the list api: the None is more then just a default thing that's returned
when nothing else is returned, but in this case its also meant as a
signal to clearly indicate that the list is modified in-place.

Every once in awhile someone asks for these methods that modify the list
itself to either return self, or return a copy of the list -- and I'm
not going to get into that debate -- but the reason for the "None" is to
make it so you WILL get errors like the above.

You only run into this situation with mutable data-types by the way:
strings ALWAYS return a copy or new string, because they can't actually
modify the string itself.