Exception not raised

[Larry Bates]

Michele Petrazzo wrote:
> Hi list, I have a strange error on my software on win 2k/xp and debian
> 3.1 with py 2.3.5 / 2.4.1 + twisted + wxpython:
> 
> python, on a piece of code doesn't raise a KeyError on a dict (that
> don't have that key), but the strange thing is that the try/except code
> see that exception. Other strange thing is that other exceptions are
> raised!
> 
> Simple example extract from my code:
> 
> #code
> def test():
>  print type(t_fields), 11 in t_fields
>  print t_fields[11]
>  print "I'm here"
> 
> print "ok"
> test()
> print "ok"
> #end code
> 
> Output:
> 
> ok
> <type 'dict'> False
> 
> Here I see only one "ok" and not the "I'm here". The interpreter stop to
> run here, but the application continue to work!
> 
> Other try:
> 
> #code
> def test():
>  try:
>   print type(t_fields), 11 in t_fields
>   print t_fields[11]
>  except KeyError, ex:
>   print "Error",  ex
> #end code
> 
> Output:
> 
> ok
> <type 'dict'> False
> Error 11
> ok
> 
> Here the output is ok, so python see that exception inside the
> try/except and print it.
> 
> Last try:
> 
> #code
> def test()
>  print type(t_fields), 11 in t_fields
>  print dont_exist
>  print t_fields[11]
> #end code
> 
> Output:
> 
> ok
> <type 'dict'> False
> File "conn.py", line 231, in test
>     print dont_exist
> NameError: global name 'dont_exist' is not defined
> 
> 
> So all the exception are raised except the KeyError outside the try/except!
> 
> I don't know what can be.
> 
> Thanks to all that can help me.
> Michele

When I run your first example I get:

>>> <type 'dict'> False
Traceback (most recent call last):
  File "C:\Python24\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py",
line 310, in RunScript
    exec codeObject in __main__.__dict__
  File "C:\Documents and Settings\larry\My Documents\junk.py", line 14, in ?
    test()
  File "C:\Documents and Settings\larry\My Documents\junk.py", line 8, in test
    print t_fields[11]
KeyError: 11
>>>

I don't know why you see anything different than a traceback when you
try to access t_fields[11] (which doesn't exist).

-Larry Bates