count item in list

[deanhystad]

What do you think should happen when you append a list to a list? Did you think it would make the original list longer? Append (and insert) treat the argument as an object, not an iterable. From the docs:

list.append(x)
Add an item to the end of the list. Equivalent to a[len(a):] = [x].

You could use extend to add items from a list to an existing list.

Output:
list.extend(iterable)
Extend the list by appending all the items from the iterable. Equivalent to a[len(a):] = iterable

And as the extend description from the manual hints, you can do the same thing with slices. You can also concatenate lists using '+'

Lists are important in Python. You need to REALLY understand how they work or it is going to come back to bite you again and again.