[Python-bugs-list] [ python-Bugs-573663 ] Type slice comparisons

[noreply@sourceforge.net]

Bugs item #573663, was opened at 2002-06-25 12:10
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=573663&group_id=5470

Category: Python Interpreter Core
Group: Python 2.2.1
Status: Closed
Resolution: Invalid
Priority: 5
Submitted By: Thomas J. Duck (tomduck)
Assigned to: Nobody/Anonymous (nobody)
Summary: Type slice comparisons

Initial Comment:
There seems to be a problem in identifing an object of
type 'slice'.  For example, the type of an integer
can be found:

     >>> type(1)
     <type 'int'>

and comparisons are correctly made:

     >>> type(1)==int
     1

However, although the type of a slice can be found:

     >>> type(slice(0,0,0))
     <type 'slice'>

comparisons don't work properly:

     >>> type(slice(0,0,0))==slice
     0

Strangely, the following operation does work:

     >>> type(slice(0,0,0))==type(slice(1,1,1))
     1

So, the behaviour for type 'slice' is at least inconsistent
with other types such as 'int'.


----------------------------------------------------------------------

>Comment By: Thomas J. Duck (tomduck)
Date: 2002-06-25 15:25

Message:
Logged In: YES 
user_id=568469

Thanks for clearing this up for me, Raymond.

Cheers, Tom


----------------------------------------------------------------------

Comment By: Raymond Hettinger (rhettinger)
Date: 2002-06-25 15:07

Message:
Logged In: YES 
user_id=80475

You're a little before your time ;)

In Python 2.2, slice() is a builtin function, which is, of 
course, not equal to a slice object.  What does work is:  
type(slice(0,0,0)) == types.SliceType

In Python 2.3, slice() is now its own type constructor and 
your comparision will work fine.

This is the documented behavior and not a bug.  
Hopefully, the upgrade to Py2.3 will make more and more 
intuitive behaviors work right out of the box :-)

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=573663&group_id=5470