[libcamera-devel] [PATCH] utils: checkstyle.py: Add pep8 checker

[Laurent Pinchart]

Hi Kieran,

Thank you for the patch.

On Thu, Jul 04, 2019 at 10:50:07AM +0100, Kieran Bingham wrote:
> On 04/07/2019 10:35, Kieran Bingham wrote:
> > Process python additions with pep8 and report any errors that are added.
> > 
> > Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > ---
> >  utils/checkstyle.py | 29 +++++++++++++++++++++++++++++
> >  1 file changed, 29 insertions(+)
> > 
> > This checker allows the checkstyle script to self-identify any issue.
> > Isn't that recursivly fun?
> > 
> > 
> > Todo:
> >   -  This should not fail if pep8 is not present, and should instead report an
> >      issue that pep8 is not installed.
> 
> For reference, this was actually easy to add.
> 
> The following is now in v2, but I'll await any further comments before
> reposting.
> 
> > -        ret = subprocess.run(['pep8', '--ignore=E501', '-'],
> > -                             input=self.__data, stdout=subprocess.PIPE)
> > +        try:
> > +            ret = subprocess.run(['pep8', '--ignore=E501', '-'],
> > +                                 input=self.__data, stdout=subprocess.PIPE)
> > +        except FileNotFoundError:
> > +            issues.append(StyleIssue(0, "", "Please install pep8 to validate python additions"))
> > +            return issues

How about doing it the same way we handle the astyle and clang-format
dependencies, in the main function ?

> >   -  The line_no_regex should ideally be compiled once per class, or globally?
> >      But how then do you access a class object from the class instance...
> >   -  All of the pep8 failures in checkstyle.py should be fixed up ...
> > 
> > diff --git a/utils/checkstyle.py b/utils/checkstyle.py
> > index fab4b116d2ff..a960affc71a9 100755
> > --- a/utils/checkstyle.py
> > +++ b/utils/checkstyle.py
> > @@ -276,6 +276,35 @@ class MesonChecker(StyleChecker):
> >          return issues
> >  
> >  
> > +class Pep8Checker(StyleChecker):
> > +    patterns = ('*.py',)
> > +
> > +    def __init__(self, content):
> > +        super().__init__()
> > +        self.__content = content
> > +        self.__data = "".join(content).encode('utf-8')

s/""/''/

It makes not difference in practice, but the script tends to use single
quotes, so let's be consistent.

There's also no need to store __data in the class, you can make it a
local variable where used.

> > +
> > +    def check(self, line_numbers):
> > +        issues = []
> > +        line_no_regex = re.compile('stdin:([0-9]+):([0-9]+)(.*)')

You can move this to the class level, below patterns, and use it with
Pep8Checker.line_no_regex.

> > +
> > +        ret = subprocess.run(['pep8', '--ignore=E501', '-'],
> > +                             input=self.__data, stdout=subprocess.PIPE)
> > +
> > +        results = ret.stdout.decode('utf-8').splitlines()
> > +        for item in results:
> > +            search = re.search(line_no_regex, item)
> > +            line_number = int(search.group(1))
> > +            position = int(search.group(2))
> > +            msg = search.group(3)
> > +
> > +            if line_number in line_numbers:
> > +                line = self.__content[line_number - 1]
> > +                issues.append(StyleIssue(line_number, line, msg))
> > +
> > +        return issues
> > +
> > +
> >  # ------------------------------------------------------------------------------
> >  # Formatters
> >  #

-- 
Regards,

Laurent Pinchart