Why == doesn't returns true in this case?

Question

I'm jython/python bukkit plugin developer and I'm stuck here. I was always using == in cases like this one, and everything worked perfect. What's the problem? Here's the code:

        lastslot = event.getNewSlot()
        iteminslot = event.getPlayer().getInventory().getItem(lastslot).getType()
        print "Iteminslot: %s "%iteminslot
        print "CurrentKey: %s"%currentKey
        if clickable1 == "false":
           log.info("clickable1 ok")
           if iteminslot == currentKey:
              log.info("iteminslot ok")
              event.getPlayer().addPotionEffect(potion_effect) 

When I run code, I get code process to the "clickable1 ok" logger, so it stops checking if iteminslot == currentKey... But when I print out Iteminslot and Currentkey, they are same!

20:41:00 [INFO] Iteminslot: DIAMOND_SWORD
20:41:00 [INFO] CurrentKey: DIAMOND_SWORD
20:41:01 [INFO] clickable1 ok

Where am I making mistakes? Thanks for reading/answering! :)

Answer 1

You're trying to compare a byte-string with a unicode string, they are not always equal. You should decode/encode them properly before comparing:

>>> 'ć' == u'ć'
False
>>> 'ć' == u'ć'.encode('utf-8')
True
>>> 'ć'.decode('utf-8') == u'ć'
True

Secondly as @BrenBarn mentioned, two objects can print out to a same string. But that doesn't means they're equal:

>>> class foo:
    def __str__(self):
        return 'foo'
...     
>>> class bar:
    def __str__(self):
        return 'foo'
...     
>>> print (foo())
foo
>>> print (bar())
foo
>>> foo == bar
False