In Python why is [2] less than (1,)?

Question

BACKGROUND

I've been trying to work out why my AI has been making some crazy moves and I traced the problem back to the following behaviour when using Python 2.7.2

>>> print [2]>[1]
True
>>> print (2,)>(1,)
True
>>> print [2]>(1,)
False                 (WHY?)

>>> print [2]<[1]
False
>>> print (2,)<(1,)
False
>>> print [2]<(1,)
True                  (WHY?)

It seems to behave as if lists are always less than tuples.

This is not what I expected from the documentation

Tuples and lists are compared lexicographically using comparison of corresponding elements. This means that to compare equal, each element must compare equal and the two sequences must be of the same type and have the same length.

If not equal, the sequences are ordered the same as their first differing elements. For example, cmp([1,2,x], [1,2,y]) returns the same as cmp(x,y). If the corresponding element does not exist, the shorter sequence is ordered first (for example, [1,2] < [1,2,3]).

QUESTION

What is going on here? Am I allowed to compare tuples and lists - or perhaps am I only allowed to compare the same type with itself?

Answer 1

Sequences are not coerced when comparing, hence their type name is compared instead.

>>> 'list' < 'tuple'
True

Answer 2

They're not the same type.

each element must compare equal and the two sequences must be of the same type and have the same length

So the comparison is being performed based on type, not on actual data stored in the sequences. On python3.x, this comparison raises a TypeError:

Python 3.2 (r32:88445, May 11 2011, 09:23:22) 
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> [2] > (1,)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unorderable types: list() > tuple()