Steven D'Aprano wrote:
On Thu, 16 Jul 2009 10:32:01 am Josiah Carlson wrote:
I use 1/0 instead of True/False because older Pythons loaded numeric constants faster than the names True/False (is that still the case?)
From Python 2.6.1:
import dis dis.dis(compile("while 1: break", "", "exec"))
1 0 SETUP_LOOP 4 (to 7) >> 3 BREAK_LOOP 4 JUMP_ABSOLUTE 3 >> 7 LOAD_CONST 0 (None) 10 RETURN_VALUE
dis.dis(compile("while True: break", "", "exec"))
1 0 SETUP_LOOP 13 (to 16) >> 3 LOAD_NAME 0 (True) 6 JUMP_IF_FALSE 5 (to 14) 9 POP_TOP 10 BREAK_LOOP 11 JUMP_ABSOLUTE 3 >> 14 POP_TOP 15 POP_BLOCK >> 16 LOAD_CONST 0 (None) 19 RETURN_VALUE
True is a constant in Python 3.0.
In 3.1
dis.dis(compile("while True: break", "", "exec"))
1 0 SETUP_LOOP 4 (to 7) >> 3 BREAK_LOOP 4 JUMP_ABSOLUTE 3 >> 7 LOAD_CONST 0 (None) 10 RETURN_VALUE
Same as while 1
tjr