[New-bugs-announce] [issue22549] bug in accessing bytes, inconsistent with normal strings and python 2.7

[Kevin Hendricks]

New submission from Kevin Hendricks:

Hi,

I am working on porting my ebook code from Python 2.7 to work with both Python 2.7 and Python 3.4 and have found the following inconsistency I think is a bug ...

KevinsiMac:~ kbhend$ python3
Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 00:54:21) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>> o = '123456789'

>>> o[-3]
'7'

>>> type(o[-3])
<class 'str'>

>>> type(o)
<class 'str'>

the above is what I expected but under python 3 for bytes you get the following instead:

>>> o = b'123456789'

>>> o[-3]
55

>>> type(o[-3])
<class 'int'>

>>> type(o)
<class 'bytes'>
 


When I compare this to Python 2.7 for both bytestrings and unicode I see the expected behaviour. 

Python 2.7.7 (v2.7.7:f89216059edf, May 31 2014, 12:53:48) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.


>>> o = '123456789'

>>> o[-3]
'7'

>>> type(o[-3])
<type 'str'>

>>> type(o)
<type 'str'>


>>> o = u'123456789'

>>> o[-3]
u'7'

>>> type(o[-3])
<type 'unicode'>

>>> type(o)
<type 'unicode'>


I would consider this a bug as it makes it much harder to write python code that works on both python 2.7 and python 3.4

----------
components: Interpreter Core
messages: 228348
nosy: kevinbhendricks
priority: normal
severity: normal
status: open
title: bug in accessing bytes, inconsistent with normal strings and python 2.7
type: behavior
versions: Python 2.7, Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue22549>
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