-3

Here is some saved interaction in command prompt.

```
>>> type((1,2))
<type 'tuple'>
>>> (3*x for x in (4,4))
<generator object <genexpr> at 0x00E73EB8>
>>> tuple(x**2 for x in range(10))
(0, 1, 4, 9, 16, 25, 36, 49, 64, 81)
>>> set(x for x in range(10))
set([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> {x:x**2 for x in range(10)}
SyntaxError: invalid syntax
>>> x=2
>>> {x:x**2}
{2: 4}
>>> [{x:x**2} for x in range(10)]
[{0: 0}, {1: 1}, {2: 4}, {3: 9}, {4: 16}, {5: 25}, {6: 36}, {7: 49}, {8: 64}, {9: 81}]
>>> type([{x:x**2} for x in range(10)])
<type 'list'>
>>> dict([[x:x**2] for x in range(10)])
SyntaxError: invalid syntax
>>> dict([[x,x**2] for x in range(10)])
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25, 6: 36, 7: 49, 8: 64, 9: 81}
>>>
```