| Message ID | 1550519997-253534-1-git-send-email-andrey.shinkevich@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iotests: handle TypeError for Python3 in test 242 | expand |
[adding Eduardo for some python 2-vs-3 advice] On 2/18/19 1:59 PM, Andrey Shinkevich wrote: > To write one byte to disk, Python2 may use 'chr' type. > In Python3, conversion to 'byte' type is required. > > Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> > --- > tests/qemu-iotests/242 | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 > index 16c65ed..6b1f7b8 100755 > --- a/tests/qemu-iotests/242 > +++ b/tests/qemu-iotests/242 > @@ -65,9 +65,14 @@ 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) > + try: > + # python2 > + f.write(chr(toggled)) > + except TypeError: > + # python3 > + f.write(bytes([toggled])) Looks like it works, but I'm not enough of a python expert to know if there is a more Pythonic elegant approach. If someone else picks it up before my next NBD pull request, Acked-by: Eric Blake <eblake@redhat.com>
On 2/18/19 9:05 PM, Eric Blake wrote: > [adding Eduardo for some python 2-vs-3 advice] And Cleber. > > On 2/18/19 1:59 PM, Andrey Shinkevich wrote: >> To write one byte to disk, Python2 may use 'chr' type. >> In Python3, conversion to 'byte' type is required. >> >> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> >> --- >> tests/qemu-iotests/242 | 9 +++++++-- >> 1 file changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 >> index 16c65ed..6b1f7b8 100755 >> --- a/tests/qemu-iotests/242 >> +++ b/tests/qemu-iotests/242 >> @@ -65,9 +65,14 @@ 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) >> + try: >> + # python2 >> + f.write(chr(toggled)) >> + except TypeError: >> + # python3 >> + f.write(bytes([toggled])) > > Looks like it works, but I'm not enough of a python expert to know if > there is a more Pythonic elegant approach. > > If someone else picks it up before my next NBD pull request, > Acked-by: Eric Blake <eblake@redhat.com> >
18.02.2019 22:59, Andrey Shinkevich wrote: > To write one byte to disk, Python2 may use 'chr' type. > In Python3, conversion to 'byte' type is required. > > Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Forget to say to Andrey that we should add Reported-by: Kevin Wolf <kwolf@redhat.com> > --- > tests/qemu-iotests/242 | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 > index 16c65ed..6b1f7b8 100755 > --- a/tests/qemu-iotests/242 > +++ b/tests/qemu-iotests/242 > @@ -65,9 +65,14 @@ 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) > + try: > + # python2 > + f.write(chr(toggled)) > + except TypeError: > + # python3 > + f.write(bytes([toggled])) > > > qemu_img_create('-f', iotests.imgfmt, disk, '1M') >
On 2/18/19 4:25 PM, Philippe Mathieu-Daudé wrote: > On 2/18/19 9:05 PM, Eric Blake wrote: >> [adding Eduardo for some python 2-vs-3 advice] > > And Cleber. > >> >> On 2/18/19 1:59 PM, Andrey Shinkevich wrote: >>> To write one byte to disk, Python2 may use 'chr' type. >>> In Python3, conversion to 'byte' type is required. >>> >>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> >>> --- >>> tests/qemu-iotests/242 | 9 +++++++-- >>> 1 file changed, 7 insertions(+), 2 deletions(-) >>> >>> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 >>> index 16c65ed..6b1f7b8 100755 >>> --- a/tests/qemu-iotests/242 >>> +++ b/tests/qemu-iotests/242 >>> @@ -65,9 +65,14 @@ 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) >>> + try: >>> + # python2 >>> + f.write(chr(toggled)) >>> + except TypeError: >>> + # python3 >>> + f.write(bytes([toggled])) >> >> Looks like it works, but I'm not enough of a python expert to know if >> there is a more Pythonic elegant approach. >> Well, there's no way around the fact that bytes in Python 3 are very different from bytes in Python 2 (just another name for a string). What I'd recommend here is to not base the type on the exception, but choose it depending on the Python version. Something like: if sys.version_info.major == 2: f.write(chr(toggled)) else: f.write(bytes([toggled])] This is cheaper than raising/catching exceptions, it's self documenting, and follows the pattern on other tests. Regards, - Cleber. >> If someone else picks it up before my next NBD pull request, >> Acked-by: Eric Blake <eblake@redhat.com> >>
On 22/02/2019 03:17, Cleber Rosa wrote: > > > On 2/18/19 4:25 PM, Philippe Mathieu-Daudé wrote: >> On 2/18/19 9:05 PM, Eric Blake wrote: >>> [adding Eduardo for some python 2-vs-3 advice] >> >> And Cleber. >> >>> >>> On 2/18/19 1:59 PM, Andrey Shinkevich wrote: >>>> To write one byte to disk, Python2 may use 'chr' type. >>>> In Python3, conversion to 'byte' type is required. >>>> >>>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> >>>> --- >>>> tests/qemu-iotests/242 | 9 +++++++-- >>>> 1 file changed, 7 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 >>>> index 16c65ed..6b1f7b8 100755 >>>> --- a/tests/qemu-iotests/242 >>>> +++ b/tests/qemu-iotests/242 >>>> @@ -65,9 +65,14 @@ 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) >>>> + try: >>>> + # python2 >>>> + f.write(chr(toggled)) >>>> + except TypeError: >>>> + # python3 >>>> + f.write(bytes([toggled])) >>> >>> Looks like it works, but I'm not enough of a python expert to know if >>> there is a more Pythonic elegant approach. >>> > > Well, there's no way around the fact that bytes in Python 3 are very > different from bytes in Python 2 (just another name for a string). > > What I'd recommend here is to not base the type on the exception, but > choose it depending on the Python version. Something like: > > if sys.version_info.major == 2: > f.write(chr(toggled)) > else: > f.write(bytes([toggled])] > > This is cheaper than raising/catching exceptions, it's self documenting, > and follows the pattern on other tests. > > Regards, > - Cleber. > Thank you very much, Cleber. I would like to write it down as that is in iotests.py : if sys.version_info.major >= 3: ... >>> If someone else picks it up before my next NBD pull request, >>> Acked-by: Eric Blake <eblake@redhat.com> >>>
diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242 index 16c65ed..6b1f7b8 100755 --- a/tests/qemu-iotests/242 +++ b/tests/qemu-iotests/242 @@ -65,9 +65,14 @@ 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) + try: + # python2 + f.write(chr(toggled)) + except TypeError: + # python3 + f.write(bytes([toggled])) qemu_img_create('-f', iotests.imgfmt, disk, '1M')
To write one byte to disk, Python2 may use 'chr' type. In Python3, conversion to 'byte' type is required. Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> --- tests/qemu-iotests/242 | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)