Jython class names

[Robin Becker]

I recently came across a problem with porting to Jython

basically the following is prints 1 in CPython, but not in Jython.

class C:
pass

red = C()
print red.__class__.__name__ is 'C'


it seems that Jython doesn't intern names in the same way or instances
are not constructed in the same way. Is the above test robust or should
I always be using == for testing class names?

 

[Erik Max Francis]

I recently came across a problem with porting to Jython

basically the following is prints 1 in CPython, but not in Jython.

class C:
pass

red = C()
print red.__class__.__name__ is 'C'

it seems that Jython doesn't intern names in the same way or instances
are not constructed in the same way. Is the above test robust or
should
I always be using == for testing class names?

You should be testing string equality with ==. Whether two strings that
are equal are actually the same string (is) is an implementation detail.

 

[Peter Otten]

I recently came across a problem with porting to Jython

basically the following is prints 1 in CPython, but not in Jython.

class C:
pass

red = C()
print red.__class__.__name__ is 'C'


it seems that Jython doesn't intern names in the same way or instances
are not constructed in the same way. Is the above test robust or should
I always be using == for testing class names?

I have no Jython around, but I expect the following to always work:

(Of course isinstance() will also return True for subclass instances)

Peter

 

[Robin Becker]

I have no Jython around, but I expect the following to always work:

I just tried and wow

True

it doesn't work

C:\jython-2.1>jython
Jython 2.1 on java1.4.2 (JIT: null)
Type "copyright", "credits" or "license" for more information.

.......

(Of course isinstance() will also return True for subclass instances)

Peter

We're using the name tests in case we get the class from different
import paths.

 

[Peter Otten]

C:\jython-2.1>jython
Jython 2.1 on java1.4.2 (JIT: null)
Type "copyright", "credits" or "license" for more information.

That's definitely not what I expected. So == is the way to go.
Still, I'm curious: would the code below return 100 in Jython?

class C: pass ....
many = [C() for i in range(100)]
d = {}
for c in many:

.... d[id(c.__class__.__name__)] = None
....1

Peter