A list is a container for variable length
sequence of Python objects. A list is mutable,
which means that items within the list can be
changed. Also, items can be added to the list or
removed from the list.
A list is an mutable sequence of Python
objects. Since it is a sequence, all of the common operations to
sequences apply. Since it is mutable, it can be changed: objects can be
added to, removed from and replaced in a
list.
Sometimes we'll see a list with a fixed
number of elements, like a two-dimensional point with two elements,
x
and
y
. When someone asks
about a fixed-length list, we have to remind them
that the tuple, covered in Chapter 14, Lists
, is for static sequences of elements.
A great deal of Python's internals a
list-based. The
for
statement,
in particular, expects a sequence, and we often create a
list by using the range
function. When we split a string using the
split method, we get a list
of substrings.