[Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Andrey Shinkevich]

The data type for bytes in Python3 differs from the one in Python2.
Those cases should be managed separately.

v1:
In the first version, the TypeError in Python3 was handled as the
exception.
Discussed in the e-mail thread with the Message ID:
<1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reported-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/242 | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
index 16c65ed..446fbf8 100755
--- a/tests/qemu-iotests/242
+++ b/tests/qemu-iotests/242
@@ -20,6 +20,7 @@
 
 import iotests
 import json
+import sys
 from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
     file_path, img_info_log, log, filter_qemu_io
 
@@ -65,9 +66,12 @@ def toggle_flag(offset):
     with open(disk, "r+b") as f:
         f.seek(offset, 0)
         c = f.read(1)
-        toggled = chr(ord(c) ^ bitmap_flag_unknown)
+        toggled = ord(c) ^ bitmap_flag_unknown
         f.seek(-1, 1)
-        f.write(toggled)
+        if sys.version_info.major >= 3:
+            f.write(bytes([toggled]))
+        else:
+            f.write(chr(toggled))
 
 
 qemu_img_create('-f', iotests.imgfmt, disk, '1M')
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Eric Blake]

On 2/22/19 5:26 AM, Andrey Shinkevich wrote:
> The data type for bytes in Python3 differs from the one in Python2.
> Those cases should be managed separately.
> 
> v1:
> In the first version, the TypeError in Python3 was handled as the
> exception.
> Discussed in the e-mail thread with the Message ID:
> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>

This paragraph belongs...

> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> ---

...here, after the --- marker. It is useful to reviewers, but does not
need to land in the long-term git history (a year from now, we won't
care if it was v2 or v10 that landed, nor how it changed from the
versions that didn't land).  I can clean it up on staging.

Reviewed-by: Eric Blake <eblake@redhat.com>

Will stage through my NBD tree.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Andrey Shinkevich]

On 22/02/2019 17:53, Eric Blake wrote:
> On 2/22/19 5:26 AM, Andrey Shinkevich wrote:
>> The data type for bytes in Python3 differs from the one in Python2.
>> Those cases should be managed separately.
>>
>> v1:
>> In the first version, the TypeError in Python3 was handled as the
>> exception.
>> Discussed in the e-mail thread with the Message ID:
>> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
> 
> This paragraph belongs...
> 
>>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>> Reported-by: Kevin Wolf <kwolf@redhat.com>
>> ---
> 
> ...here, after the --- marker. It is useful to reviewers, but does not
> need to land in the long-term git history (a year from now, we won't
> care if it was v2 or v10 that landed, nor how it changed from the
> versions that didn't land).  I can clean it up on staging.
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> Will stage through my NBD tree.
> 

Yes, please, Eric. Actually, I had missed to put that paragraph bellow
the dashes while composing it as a cover letter. That was my fault.
Acknowledged with thanks. I will take your comment into account for
future.

-- 
With the best regards,
Andrey Shinkevich

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Cleber Rosa]

On 2/22/19 6:26 AM, Andrey Shinkevich wrote:
> The data type for bytes in Python3 differs from the one in Python2.
> Those cases should be managed separately.
> 
> v1:
> In the first version, the TypeError in Python3 was handled as the
> exception.
> Discussed in the e-mail thread with the Message ID:
> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  tests/qemu-iotests/242 | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
> index 16c65ed..446fbf8 100755
> --- a/tests/qemu-iotests/242
> +++ b/tests/qemu-iotests/242
> @@ -20,6 +20,7 @@
>  
>  import iotests
>  import json
> +import sys
>  from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
>      file_path, img_info_log, log, filter_qemu_io
>  
> @@ -65,9 +66,12 @@ def toggle_flag(offset):
>      with open(disk, "r+b") as f:
>          f.seek(offset, 0)
>          c = f.read(1)
> -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> +        toggled = ord(c) ^ bitmap_flag_unknown
>          f.seek(-1, 1)
> -        f.write(toggled)
> +        if sys.version_info.major >= 3:
> +            f.write(bytes([toggled]))
> +        else:
> +            f.write(chr(toggled))
>  

I originally suggested:

sys.version_info.major == 2:
 ...

Because this is already present on other tests, and IIRC Max mentioned
using this as an easy to find flag the moment Python 2 support is to be
dropped.  But, looking for "sys.version_info.major" is just as
effective, so:

Reviewed-by: Cleber Rosa <crosa@redhat.com>

>  
>  qemu_img_create('-f', iotests.imgfmt, disk, '1M')
> 

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Andrey Shinkevich]

On 22/02/2019 18:20, Cleber Rosa wrote:
> 
> 
> On 2/22/19 6:26 AM, Andrey Shinkevich wrote:
>> The data type for bytes in Python3 differs from the one in Python2.
>> Those cases should be managed separately.
>>
>> v1:
>> In the first version, the TypeError in Python3 was handled as the
>> exception.
>> Discussed in the e-mail thread with the Message ID:
>> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
>>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>> Reported-by: Kevin Wolf <kwolf@redhat.com>
>> ---
>>   tests/qemu-iotests/242 | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
>> index 16c65ed..446fbf8 100755
>> --- a/tests/qemu-iotests/242
>> +++ b/tests/qemu-iotests/242
>> @@ -20,6 +20,7 @@
>>   
>>   import iotests
>>   import json
>> +import sys
>>   from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
>>       file_path, img_info_log, log, filter_qemu_io
>>   
>> @@ -65,9 +66,12 @@ def toggle_flag(offset):
>>       with open(disk, "r+b") as f:
>>           f.seek(offset, 0)
>>           c = f.read(1)
>> -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
>> +        toggled = ord(c) ^ bitmap_flag_unknown
>>           f.seek(-1, 1)
>> -        f.write(toggled)
>> +        if sys.version_info.major >= 3:
>> +            f.write(bytes([toggled]))
>> +        else:
>> +            f.write(chr(toggled))
>>   
> 
> I originally suggested:
> 
> sys.version_info.major == 2:
>   ...
> 
> Because this is already present on other tests, and IIRC Max mentioned
> using this as an easy to find flag the moment Python 2 support is to be
> dropped.  But, looking for "sys.version_info.major" is just as
> effective, so:
> 
> Reviewed-by: Cleber Rosa <crosa@redhat.com>
> 

Thank you very much, Cleber. Your review is helpful.

>>   
>>   qemu_img_create('-f', iotests.imgfmt, disk, '1M')
>>

-- 
With the best regards,
Andrey Shinkevich

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Vladimir Sementsov-Ogievskiy]

22.02.2019 14:26, Andrey Shinkevich wrote:
> The data type for bytes in Python3 differs from the one in Python2.
> Those cases should be managed separately.
> 
> v1:
> In the first version, the TypeError in Python3 was handled as the
> exception.
> Discussed in the e-mail thread with the Message ID:
> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   tests/qemu-iotests/242 | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
> index 16c65ed..446fbf8 100755
> --- a/tests/qemu-iotests/242
> +++ b/tests/qemu-iotests/242
> @@ -20,6 +20,7 @@
>   
>   import iotests
>   import json
> +import sys
>   from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
>       file_path, img_info_log, log, filter_qemu_io
>   
> @@ -65,9 +66,12 @@ def toggle_flag(offset):
>       with open(disk, "r+b") as f:
>           f.seek(offset, 0)
>           c = f.read(1)
> -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> +        toggled = ord(c) ^ bitmap_flag_unknown
>           f.seek(-1, 1)
> -        f.write(toggled)
> +        if sys.version_info.major >= 3:
> +            f.write(bytes([toggled]))
> +        else:
> +            f.write(chr(toggled))
>   
>   
>   qemu_img_create('-f', iotests.imgfmt, disk, '1M')
> 

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

-- 
Best regards,
Vladimir

Re: [Qemu-devel] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Eduardo Habkost]

On Fri, Feb 22, 2019 at 02:26:13PM +0300, Andrey Shinkevich wrote:
> The data type for bytes in Python3 differs from the one in Python2.
> Those cases should be managed separately.
> 
> v1:
> In the first version, the TypeError in Python3 was handled as the
> exception.
> Discussed in the e-mail thread with the Message ID:
> <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  tests/qemu-iotests/242 | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
> index 16c65ed..446fbf8 100755
> --- a/tests/qemu-iotests/242
> +++ b/tests/qemu-iotests/242
> @@ -20,6 +20,7 @@
>  
>  import iotests
>  import json
> +import sys
>  from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
>      file_path, img_info_log, log, filter_qemu_io
>  
> @@ -65,9 +66,12 @@ def toggle_flag(offset):
>      with open(disk, "r+b") as f:
>          f.seek(offset, 0)
>          c = f.read(1)
> -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> +        toggled = ord(c) ^ bitmap_flag_unknown
>          f.seek(-1, 1)
> -        f.write(toggled)
> +        if sys.version_info.major >= 3:
> +            f.write(bytes([toggled]))
> +        else:
> +            f.write(chr(toggled))

Pretending we are dealing with text strings and using str/ord is
a python2-specific quirk.  I think it would be nice to get rid of
it.

Python 2 has bytearray(), which behaves more similarly to the
bytes type from Python 3.  If we use it, we can make the code
more python3-like:

diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
index 16c65edcd7..7794fd4a70 100755
--- a/tests/qemu-iotests/242
+++ b/tests/qemu-iotests/242
@@ -64,10 +64,12 @@ def write_to_disk(offset, size):
 def toggle_flag(offset):
     with open(disk, "r+b") as f:
         f.seek(offset, 0)
-        c = f.read(1)
-        toggled = chr(ord(c) ^ bitmap_flag_unknown)
+        # The casts to bytearray() below are only necessary
+        # for Python 2 compatibility
+        c = bytearray(f.read(1))[0]
+        toggled = c ^ bitmap_flag_unknown
         f.seek(-1, 1)
-        f.write(toggled)
+        f.write(bytearray([toggled]))
 
 
 qemu_img_create('-f', iotests.imgfmt, disk, '1M')

-- 
Eduardo

Re: [Qemu-devel] [Qemu-block] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Nir Soffer]

On Mon, Feb 25, 2019 at 10:36 PM Eduardo Habkost <ehabkost@redhat.com>
wrote:

> On Fri, Feb 22, 2019 at 02:26:13PM +0300, Andrey Shinkevich wrote:
> > The data type for bytes in Python3 differs from the one in Python2.
> > Those cases should be managed separately.
> >
> > v1:
> > In the first version, the TypeError in Python3 was handled as the
> > exception.
> > Discussed in the e-mail thread with the Message ID:
> > <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>
> >
> > Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> > Reported-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >  tests/qemu-iotests/242 | 8 ++++++--
> >  1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
> > index 16c65ed..446fbf8 100755
> > --- a/tests/qemu-iotests/242
> > +++ b/tests/qemu-iotests/242
> > @@ -20,6 +20,7 @@
> >
> >  import iotests
> >  import json
> > +import sys
> >  from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
> >      file_path, img_info_log, log, filter_qemu_io
> >
> > @@ -65,9 +66,12 @@ def toggle_flag(offset):
> >      with open(disk, "r+b") as f:
> >          f.seek(offset, 0)
> >          c = f.read(1)
> > -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> > +        toggled = ord(c) ^ bitmap_flag_unknown
> >          f.seek(-1, 1)
> > -        f.write(toggled)
> > +        if sys.version_info.major >= 3:
> > +            f.write(bytes([toggled]))
> > +        else:
> > +            f.write(chr(toggled))
>
> Pretending we are dealing with text strings and using str/ord is
> a python2-specific quirk.  I think it would be nice to get rid of
> it.
>
> Python 2 has bytearray(), which behaves more similarly to the
> bytes type from Python 3.  If we use it, we can make the code
> more python3-like:
>
> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
> index 16c65edcd7..7794fd4a70 100755
> --- a/tests/qemu-iotests/242
> +++ b/tests/qemu-iotests/242
> @@ -64,10 +64,12 @@ def write_to_disk(offset, size):
>  def toggle_flag(offset):
>      with open(disk, "r+b") as f:
>          f.seek(offset, 0)
> -        c = f.read(1)
> -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> +        # The casts to bytearray() below are only necessary
> +        # for Python 2 compatibility
> +        c = bytearray(f.read(1))[0]
>

This is simpler and makes the intent of the code more clear:

    flag, = struct.unpack("B", f.read(1))


> +        toggled = c ^ bitmap_flag_unknown
>          f.seek(-1, 1)
> -        f.write(toggled)
> +        f.write(bytearray([toggled]))
>

For consistency, we can use struct.pack here:

    f.write(struct.pack("B", toggled))

Nir


>
>
>  qemu_img_create('-f', iotests.imgfmt, disk, '1M')
>
> --
> Eduardo
>
>

Re: [Qemu-devel] [Qemu-block] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Andrey Shinkevich]

On 26/02/2019 04:42, Nir Soffer wrote:
> On Mon, Feb 25, 2019 at 10:36 PM Eduardo Habkost <ehabkost@redhat.com 
> <mailto:ehabkost@redhat.com>> wrote:
> 
>     On Fri, Feb 22, 2019 at 02:26:13PM +0300, Andrey Shinkevich wrote:
>      > The data type for bytes in Python3 differs from the one in Python2.
>      > Those cases should be managed separately.
>      >
>      > v1:
>      > In the first version, the TypeError in Python3 was handled as the
>      > exception.
>      > Discussed in the e-mail thread with the Message ID:
>      >
>     <1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com
>     <mailto:1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com>>
>      >
>      > Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com
>     <mailto:andrey.shinkevich@virtuozzo.com>>
>      > Reported-by: Kevin Wolf <kwolf@redhat.com <mailto:kwolf@redhat.com>>
>      > ---
>      >  tests/qemu-iotests/242 | 8 ++++++--
>      >  1 file changed, 6 insertions(+), 2 deletions(-)
>      >
>      > diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
>      > index 16c65ed..446fbf8 100755
>      > --- a/tests/qemu-iotests/242
>      > +++ b/tests/qemu-iotests/242
>      > @@ -20,6 +20,7 @@
>      >
>      >  import iotests
>      >  import json
>      > +import sys
>      >  from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
>      >      file_path, img_info_log, log, filter_qemu_io
>      >
>      > @@ -65,9 +66,12 @@ def toggle_flag(offset):
>      >      with open(disk, "r+b") as f:
>      >          f.seek(offset, 0)
>      >          c = f.read(1)
>      > -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
>      > +        toggled = ord(c) ^ bitmap_flag_unknown
>      >          f.seek(-1, 1)
>      > -        f.write(toggled)
>      > +        if sys.version_info.major >= 3:
>      > +            f.write(bytes([toggled]))
>      > +        else:
>      > +            f.write(chr(toggled))
> 
>     Pretending we are dealing with text strings and using str/ord is
>     a python2-specific quirk.  I think it would be nice to get rid of
>     it.
> 
>     Python 2 has bytearray(), which behaves more similarly to the
>     bytes type from Python 3.  If we use it, we can make the code
>     more python3-like:
> 
>     diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
>     index 16c65edcd7..7794fd4a70 100755
>     --- a/tests/qemu-iotests/242
>     +++ b/tests/qemu-iotests/242
>     @@ -64,10 +64,12 @@ def write_to_disk(offset, size):
>       def toggle_flag(offset):
>           with open(disk, "r+b") as f:
>               f.seek(offset, 0)
>     -        c = f.read(1)
>     -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
>     +        # The casts to bytearray() below are only necessary
>     +        # for Python 2 compatibility
>     +        c = bytearray(f.read(1))[0]
> 
> 
> This is simpler and makes the intent of the code more clear:
> 
>      flag, = struct.unpack("B", f.read(1))
> 
>     +        toggled = c ^ bitmap_flag_unknown
>               f.seek(-1, 1)
>     -        f.write(toggled)
>     +        f.write(bytearray([toggled]))
> 
> 
> For consistency, we can use struct.pack here:
> 
>      f.write(struct.pack("B", toggled))
> 
> Nir
> 

Thank you all. I am OK with this approach.
Will wait for Eric's response.

> 
> 
>       qemu_img_create('-f', iotests.imgfmt, disk, '1M')
> 
>     -- 
>     Eduardo
> 

-- 
With the best regards,
Andrey Shinkevich

Re: [Qemu-devel] [Qemu-block] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Eric Blake]

On 2/26/19 4:39 AM, Andrey Shinkevich wrote:

>>     +++ b/tests/qemu-iotests/242
>>     @@ -64,10 +64,12 @@ def write_to_disk(offset, size):
>>       def toggle_flag(offset):
>>           with open(disk, "r+b") as f:
>>               f.seek(offset, 0)
>>     -        c = f.read(1)
>>     -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
>>     +        # The casts to bytearray() below are only necessary
>>     +        # for Python 2 compatibility
>>     +        c = bytearray(f.read(1))[0]
>>
>>
>> This is simpler and makes the intent of the code more clear:
>>
>>      flag, = struct.unpack("B", f.read(1))
>>
>>     +        toggled = c ^ bitmap_flag_unknown
>>               f.seek(-1, 1)
>>     -        f.write(toggled)
>>     +        f.write(bytearray([toggled]))
>>
>>
>> For consistency, we can use struct.pack here:
>>
>>      f.write(struct.pack("B", toggled))
>>
>> Nir
>>
> 
> Thank you all. I am OK with this approach.
> Will wait for Eric's response.

That looks better. Peter hasn't applied my pull request yet, so you have
time to submit a formal v3 (making it easier for me to 'git am' it
rather than reconstruct from this email), and then I will update my pull
request to use this improved version.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [Qemu-block] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Andrey Shinkevich]

On 26/02/2019 17:06, Eric Blake wrote:
> On 2/26/19 4:39 AM, Andrey Shinkevich wrote:
> 
>>>      +++ b/tests/qemu-iotests/242
>>>      @@ -64,10 +64,12 @@ def write_to_disk(offset, size):
>>>        def toggle_flag(offset):
>>>            with open(disk, "r+b") as f:
>>>                f.seek(offset, 0)
>>>      -        c = f.read(1)
>>>      -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
>>>      +        # The casts to bytearray() below are only necessary
>>>      +        # for Python 2 compatibility
>>>      +        c = bytearray(f.read(1))[0]
>>>
>>>
>>> This is simpler and makes the intent of the code more clear:
>>>
>>>       flag, = struct.unpack("B", f.read(1))
>>>
>>>      +        toggled = c ^ bitmap_flag_unknown
>>>                f.seek(-1, 1)
>>>      -        f.write(toggled)
>>>      +        f.write(bytearray([toggled]))
>>>
>>>
>>> For consistency, we can use struct.pack here:
>>>
>>>       f.write(struct.pack("B", toggled))
>>>
>>> Nir
>>>
>>
>> Thank you all. I am OK with this approach.
>> Will wait for Eric's response.
> 
> That looks better. Peter hasn't applied my pull request yet, so you have
> time to submit a formal v3 (making it easier for me to 'git am' it
> rather than reconstruct from this email), and then I will update my pull
> request to use this improved version.
> 
Noted

-- 
With the best regards,
Andrey Shinkevich

Re: [Qemu-devel] [Qemu-block] [PATCH v2] iotests: handle TypeError for Python3 in test 242

[Eduardo Habkost]

On Tue, Feb 26, 2019 at 03:42:11AM +0200, Nir Soffer wrote:
> On Mon, Feb 25, 2019 at 10:36 PM Eduardo Habkost <ehabkost@redhat.com>
[...]
> > -        c = f.read(1)
> > -        toggled = chr(ord(c) ^ bitmap_flag_unknown)
> > +        # The casts to bytearray() below are only necessary
> > +        # for Python 2 compatibility
> > +        c = bytearray(f.read(1))[0]
> >
> 
> This is simpler and makes the intent of the code more clear:
> 
>     flag, = struct.unpack("B", f.read(1))
> 
> 
> > +        toggled = c ^ bitmap_flag_unknown
> >          f.seek(-1, 1)
> > -        f.write(toggled)
> > +        f.write(bytearray([toggled]))
> >
> 
> For consistency, we can use struct.pack here:
> 
>     f.write(struct.pack("B", toggled))

That's perfect.  Thanks for the suggestion!

-- 
Eduardo