Re: 2 + 2 = 5

2012-07-15 Thread samuel . marks
On Friday, July 6, 2012 8:39:58 AM UTC+10, Andrew Cooper wrote: > On 05/07/2012 22:46, Evan Driscoll wrote: > > On 01/-10/-28163 01:59 PM, Alexander Blinne wrote: > >> 5+0 is actually 4+0, because 5 == 4, so 5+0 gives 4. > >> 5+1 is actually 4+1, which is 5, but 5 is again 4. > >> 5+2 is 4+2 which

Re: 2 + 2 = 5

2012-07-05 Thread Steven D'Aprano
On Thu, 05 Jul 2012 16:46:48 -0500, Evan Driscoll wrote: > On 01/-10/-28163 01:59 PM, Alexander Blinne wrote: >> 5+0 is actually 4+0, because 5 == 4, so 5+0 gives 4. 5+1 is actually >> 4+1, which is 5, but 5 is again 4. 5+2 is 4+2 which is 6. > > Now all I can think is "Hoory for new math, new-ho

Re: 2 + 2 = 5

2012-07-05 Thread Andrew Cooper
On 05/07/2012 22:46, Evan Driscoll wrote: > On 01/-10/-28163 01:59 PM, Alexander Blinne wrote: >> 5+0 is actually 4+0, because 5 == 4, so 5+0 gives 4. >> 5+1 is actually 4+1, which is 5, but 5 is again 4. >> 5+2 is 4+2 which is 6. > > Now all I can think is "Hoory for new math, new-hoo-hoo math" :

Re: 2 + 2 = 5

2012-07-05 Thread Rhodri James
On Wed, 04 Jul 2012 20:37:25 +0100, Paul Rubin wrote: I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 + 2 == 5) # False five.content

Re: Re: 2 + 2 = 5

2012-07-05 Thread Evan Driscoll
On 01/-10/-28163 01:59 PM, Alexander Blinne wrote: 5+0 is actually 4+0, because 5 == 4, so 5+0 gives 4. 5+1 is actually 4+1, which is 5, but 5 is again 4. 5+2 is 4+2 which is 6. Now all I can think is "Hoory for new math, new-hoo-hoo math" :-) Evan -- http://mail.python.org/mailman/listinfo/py

Re: 2 + 2 = 5

2012-07-05 Thread Hans Mulder
On 5/07/12 19:03:57, Alexander Blinne wrote: > On 05.07.2012 16:34, Laszlo Nagy wrote: > five.contents[five.contents[:].index(5)] = 4 > 5 >> 4 > 5 is 4 >> True > That's surprising, because even after changing 5 to 4 both objects still > have different id()s (tested on Py2.7), so 5 is 4

Re: 2 + 2 = 5

2012-07-05 Thread Alexander Blinne
On 05.07.2012 16:34, Laszlo Nagy wrote: five.contents[five.contents[:].index(5)] = 4 5 > 4 5 is 4 > True That's surprising, because even after changing 5 to 4 both objects still have different id()s (tested on Py2.7), so 5 is 4 /should/ still be False (But isn't on my 2.7). But that

Re: 2 + 2 = 5

2012-07-05 Thread Steven D'Aprano
On Thu, 05 Jul 2012 15:57:53 +0200, Hans Mulder wrote: > On 5/07/12 07:32:48, Steven D'Aprano wrote: >> On Wed, 04 Jul 2012 23:38:17 -0400, Terry Reedy wrote: >> >>> If I run the script in 3.3 Idle, I get the same output you got. If I >>> then enter '5-2' interactively, I still get 3. Maybe the c

Re: 2 + 2 = 5

2012-07-05 Thread Devin Jeanpierre
On Thu, Jul 5, 2012 at 10:34 AM, Laszlo Nagy wrote: 5+1 > 4 4 + 1 is 5 is 4. (e.g. try 2+3 as well). -- Devin -- http://mail.python.org/mailman/listinfo/python-list

Re: 2 + 2 = 5

2012-07-05 Thread MRAB
On 05/07/2012 15:34, Laszlo Nagy wrote: On 2012-07-04 21:37, Paul Rubin wrote: I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 + 2 ==

Re: 2 + 2 = 5

2012-07-05 Thread Laszlo Nagy
On 2012-07-04 21:37, Paul Rubin wrote: I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 + 2 == 5) # False five.contents[five.conten

Re: 2 + 2 = 5

2012-07-05 Thread Hans Mulder
On 5/07/12 07:32:48, Steven D'Aprano wrote: > On Wed, 04 Jul 2012 23:38:17 -0400, Terry Reedy wrote: > >> If I run the script in 3.3 Idle, I get the same output you got. If I >> then enter '5-2' interactively, I still get 3. Maybe the constant folder >> is always on now. > > Yes, I believe consta

Re: 2 + 2 = 5

2012-07-04 Thread Steven D'Aprano
On Wed, 04 Jul 2012 23:38:17 -0400, Terry Reedy wrote: > If I run the script in 3.3 Idle, I get the same output you got. If I > then enter '5-2' interactively, I still get 3. Maybe the constant folder > is always on now. Yes, I believe constant folding is always on, since Python 2.4 if I remembe

Re: 2 + 2 = 5

2012-07-04 Thread Terry Reedy
On 7/4/2012 4:37 PM, Michael Ross wrote: Am 04.07.2012, 21:37 Uhr, schrieb Paul Rubin : I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 +

Re: 2 + 2 = 5

2012-07-04 Thread Cameron Simpson
On 04Jul2012 19:39, Evan Driscoll wrote: | On 7/4/2012 14:37, Paul Rubin wrote: | > I just came across this (https://gist.github.com/1208215): | > | > import sys | > import ctypes | > pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) | > five = ctypes.cast(id(5), pyint_p) |

Re: 2 + 2 = 5

2012-07-04 Thread Evan Driscoll
On 7/4/2012 14:37, Paul Rubin wrote: > I just came across this (https://gist.github.com/1208215): > > import sys > import ctypes > pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) > five = ctypes.cast(id(5), pyint_p) > print(2 + 2 == 5) # False > five.contents[five.

Re: 2 + 2 = 5

2012-07-04 Thread Thomas Jollans
On 07/04/2012 09:37 PM, Paul Rubin wrote: > I just came across this (https://gist.github.com/1208215): > > import sys > import ctypes > pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) > five = ctypes.cast(id(5), pyint_p) > print(2 + 2 == 5) # False > five.contents[

Re: 2 + 2 = 5

2012-07-04 Thread Mark Lawrence
On 04/07/2012 20:37, Paul Rubin wrote: I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 + 2 == 5) # False five.contents[five.conten

Re: 2 + 2 = 5

2012-07-04 Thread Michael Ross
Am 04.07.2012, 21:37 Uhr, schrieb Paul Rubin : I just came across this (https://gist.github.com/1208215): import sys import ctypes pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) five = ctypes.cast(id(5), pyint_p) print(2 + 2 == 5) # False five.contents[five.con

Re: 2 + 2 = 5

2012-07-04 Thread Stefan Behnel
Paul Rubin, 04.07.2012 21:37: > I just came across this (https://gist.github.com/1208215): > > import sys > import ctypes > pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5)) > five = ctypes.cast(id(5), pyint_p) > print(2 + 2 == 5) # False > five.contents[five.content