Short, crazy example: list-derived class, with __iadd__

[Moon]

class Vec(list):
def __init__(self):
list.__init__(self, [0.0, 0.0])

def __iadd__(self, other):
assert isinstance(other, Vec)
self[0] += other[0]
self[1] += other[1]
print "right now, v is: ", self, " as you'd expect"


v = Vec()
w = Vec()
w[0] = 1.0
w[1] = 2.0
print "v starts:", v

print "(w is:", w, " which is fine)"

v += w

print "(w still is:", w

print "after iadd, v: ", v, " <-- becomes None! What the hey?"


# - running it: 

py> python badvec.py
v starts: [0.0, 0.0]
(w is: [1.0, 2.0]  which is fine)
right now, v is:  [1.0, 2.0]
(w still is: [1.0, 2.0]
later, v is:  None  <-- becomes None! What the hey?

py> python -V
Python 2.5.1

-- Any explanation from a guru?  

Thanks much...
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Short, crazy example: list-derived class, with __iadd__ <- nevermind, me == idiot

[Moon]

__iadd__ is supposed to /return/ something, most likely self. 

My bad. 

On Wed, 29 Aug 2007 20:49:59 +, Moon wrote:

> class Vec(list):
> def __init__(self):
> list.__init__(self, [0.0, 0.0])
> 
> def __iadd__(self, other):
> assert isinstance(other, Vec)
> self[0] += other[0]
> self[1] += other[1]
> print "right now, v is: ", self, " as you'd expect"
> 
> 
> v = Vec()
> w = Vec()
> w[0] = 1.0
> w[1] = 2.0
> print "v starts:", v
> 
> print "(w is:", w, " which is fine)"
> 
> v += w
> 
> print "(w still is:", w
> 
> print "after iadd, v: ", v, " <-- becomes None! What the hey?"
> 
> 
> # - running it:
> 
> py> python badvec.py
> v starts: [0.0, 0.0]
> (w is: [1.0, 2.0]  which is fine)
> right now, v is:  [1.0, 2.0]
> (w still is: [1.0, 2.0]
> later, v is:  None  <-- becomes None! What the hey?
> 
> py> python -V
> Python 2.5.1
> 
> -- Any explanation from a guru?
> 
> Thanks much...

-- 
http://mail.python.org/mailman/listinfo/python-list

Hello

[moon khondkar]

Hello I have problem with python installation.I downloaded python 3.5 but I 
cannot use it on my computer.I can not open the idle. I get something like 
saying "users\local settings\Application 
data\programs\python\python35-32\pythonw.exe is not valid win32 application. 
Thanks that will be help if you can solve this.
-- 
https://mail.python.org/mailman/listinfo/python-list

python for net manager

[moon sky]

hi there,
i just want to write a small tool to manage the network, including detect
the ip addr,netmask, and send the arp request to  find out locale's ip-mac
turtple,
is there any way to succeed this exlude 'subprocess call'?
thanks
-- 
http://mail.python.org/mailman/listinfo/python-list

why does Py_Finalize() always crashes?

[Moon In Pale]

I used Python as embeded in C++ program, which is made up of a EXE and a 
DLL. Py_Initialize() and Py_Finalize() are put in DllMain().
But everytime after the program starts, an "Access Violation" will be 
thrown. I looked up the Assembly code, the crash appears after 
Py_Finalize() returns:
 }else if(dwReason == DLL_PROCESS_DETACH){1000B4B9  test    
eax,eax 1000B4BB  
jne DllMain+23h (1000B4C3h) 
  Py_Finalize();1000B4BD  call    
dword ptr [__imp__Py_Finalize (1000E1A0h)] 
 } return true;1000B4C3  
mov 
al,1    
<-- 0xC005 thrown by 
here}1000B4C5  
ret 0Ch  
 
What may be the probable reason that caused this error? Thank 
you:)
-- 
http://mail.python.org/mailman/listinfo/python-list