Steven Bethard a écrit :
> Steven D'Aprano wrote:
>
>> I would love to see your test code and profiling results that demonstrate
>> that explicit tuple unpacking in the body of a function is faster than
>> tuple unpacking (implicit or explicit) in the header of a function.
>
>
> Should be pretty close. I believe the byte-code is nearly identical:
You forgot the most important function : f3
>>> def f1((x,y)):
... print x,y
...
>>> def f2(x_y):
... x,y = x_y
... print x,y
...
>>> def f3(x_y):
... print x_y[0], x_y[1]
...
>>> import dis
>>> dis.dis(f1)
1 0 LOAD_FAST 0 (.0)
3 UNPACK_SEQUENCE 2
6 STORE_FAST 1 (x)
9 STORE_FAST 2 (y)
2 12 LOAD_FAST 1 (x)
15 PRINT_ITEM
16 LOAD_FAST 2 (y)
19 PRINT_ITEM
20 PRINT_NEWLINE
21 LOAD_CONST 0 (None)
24 RETURN_VALUE
>>> dis.dis(f2)
2 0 LOAD_FAST 0 (x_y)
3 UNPACK_SEQUENCE 2
6 STORE_FAST 2 (x)
9 STORE_FAST 1 (y)
3 12 LOAD_FAST 2 (x)
15 PRINT_ITEM
16 LOAD_FAST 1 (y)
19 PRINT_ITEM
20 PRINT_NEWLINE
21 LOAD_CONST 0 (None)
24 RETURN_VALUE
>>> dis.dis(f3)
2 0 LOAD_FAST 0 (x_y)
3 LOAD_CONST 1 (0)
6 BINARY_SUBSCR
7 PRINT_ITEM
8 LOAD_FAST 0 (x_y)
11 LOAD_CONST 2 (1)
14 BINARY_SUBSCR
15 PRINT_ITEM
16 PRINT_NEWLINE
17 LOAD_CONST 0 (None)
20 RETURN_VALUE
>>>
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