Re: [Jython-users] string.replace( java.lang.String )

[Oti <oh...@ya...>]

[ Samuele Pedroni ]

> From: Oti <oh...@ya...>
> > Hello,
> > 
> > I just stumbled over the following behaviour of string.replace().
> > Is it true I cannot pass a java.lang.String as first argument:
> > 
> > [appl|pwe] > jython
> > Jython 2.1 on java1.3.0 (JIT: null)
> > Type "copyright", "credits" or "license" for more information.
> > >>> import string
> > >>> from java.lang import String
> > >>> old = String( "old" )
> > >>> string.replace( old, "l", "d" )
> > Traceback (innermost last):
> >   File "<console>", line 1, in ?
> >   File "e:\jython21\Lib\string.py", line 409, in replace
> > TypeError: replace(): expected 2 args; got 3
> > >>> string.replace( old.intern(), "l", "d" )
> > 'odd'
> > 
> > 
> 
> Yes, the odd behavior is expected.
> 
> You should consider that string.py is coded
> assuming Python string input, and simply
> using the Python string object methods.
> 
> so string.replace(s,old,new,maxsplit)
> 
> simply calls s.replace(old,new,maxsplit)
> 
> now perchance Java strings have a replace method
> which takes only 2 arguments.
> 
> The other thing to consider 
> is that Java constructors
> called from Jython do not convert the result, its 
> Java instance nature is preserved.
> OTOH normal Java methods have their
> results always converted following the usual
> rules (eg. java.lang.String -> string):
> 
> >>> from java.lang import String
> >>> s=String("java")
> >>> s.__class__
> <jclass java.lang.String at 8070355>
> >>> type(s)
> <jclass org.python.core.PyJavaInstance at 6040101>
> >>> s2=s.toString()
> >>> type(s) == type('')
> 0
> >>> type(s2) == type('')
> 1
> 
> The following also fails:
> >>> s+'__'
> Traceback (innermost last):
>   File "<console>", line 1, in ?
> TypeError: __add__ nor __radd__ defined for these operands
> 
> I don't know if we should change all this.

No, I think you shouldn't.

Thank you very much for your explanation.
As you might havae guessed, I am (still) struggling to upgrade from
good old JPython1.0.3, where the example above ran.
I hope these are rare cases.

Best wishes,
Oti.

__________________________________________________
Do You Yahoo!?
Try FREE Yahoo! Mail - the world's greatest free email!
http://mail.yahoo.com/