 <p>From the <a href="http://www.python.org/doc/faq/general/#why-are-there-separate-tuple-and-list-data-types" rel="nofollow noreferrer">Python FAQ</a>:</p> <blockquote> <p>Lists and tuples, while similar in many respects, are generally used in fundamentally different ways. Tuples can be thought of as being similar to Pascal records or C structs; they're small collections of related data which may be of different types which are operated on as a group. For example, a Cartesian coordinate is appropriately represented as a tuple of two or three numbers.</p> <p>Lists, on the other hand, are more like arrays in other languages. They tend to hold a varying number of objects all of which have the same type and which are operated on one-by-one.</p> </blockquote> <p>Generally by convention you wouldn't choose a list or a tuple just based on its (im)mutability. You would choose a tuple for small collections of completely different pieces of data in which a full-blown class would be too heavyweight, and a list for collections of any reasonable size where you have a homogeneous set of data.</p>