[Python-ideas] PEP 8 coding style included in grammar ?

[Mathieu BEAL]

I was wondering why the PEP coding style (
https://www.python.org/dev/peps/pep-0008/) is not natively included in
python grammar ?

For instance, both, *function definition* and *class definition*, are using
the same “NAME” token. ((see,
https://docs.python.org/3/reference/grammar.html).

classdef: 'class' NAME ['(' [arglist] ')'] ':' suite

funcdef: 'def' NAME parameters ['->' test] ':' suite


Then, we are using libraries like pyflake, flake8, pylint, to check the
coding style.


It seems useful to natively make distinction between NAME of classdef and
NAME of funcdef, with something like:

classdef: 'class' NAME_CLASS ['(' [arglist] ')'] ':' suite

funcdef: 'def' NAME_FUNC parameters ['->' test] ':' suite


NAME_CLASS:

·         Class name should normally use the CapWord convention;

NAME_FUNC:

·         Function name should be lowercase, with words separated by
underscore as necessary to improve readability,

·         mixedCase is allowed;

STYLE_CAP_WORDS = r’([A-Z]{1}[a-z]+(_[A-Z]{1}[a-z]+)*)’

STYLE_UNDERSCORE_LOW_WORDS = r’([a-z]+(_[a-z]+)*)’

STYLE_MIXED_CASE = r’([a-z]{1,}([A-Z]{1}[a-z]+)*’)

NAME_FUNC = STYLE_LOW_WORDS

                         | STYLE_UNDERSCORE_LOW_WORDS

                         | STYLE_MIXED_CASE

NAME_CLASS = STYLE_CAP_WORDS

             | NAME_FUNC   # naming convention for functions may be used in
cases where the interface is documented and used primarily as a callable
(pep8 source).



I didn't find any information about this point in a previous post or
elsewhere. Is there any reason for such a choice ? or is it a dark old
discussion we never talk about ?


Mathieu


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

 import re



# Testing the first part of the class def, only.

style_cap_words = r'^class ([A-Z]{1}[a-z]+(_?[A-Z]{1}[a-z]+)*)$'

compiled_style_cap_words = re.compile(style_cap_words)



status_samples = {True:['class Hello',

                        'class Hel_Lo', # ok if Hel and Lo are 2 words

                        'class HelLo', # same.

                    ],

                 False:['class HellO',

                        'class _He',

                        'class HEllo',

                        'class HE',

                        'class H',

                        'class h',

                        'class Hell_oo',

                        'class Hell_',

                        'class _hell',

                        'class H_E_L_L_O',

                        'class _H']}



def is_matched(sample, pattern=compiled_style_cap_words):

    matched = pattern.match(sample)

    return matched is not None



for status, samples in status_samples.items():

    for sample in samples:

        is_correct = status == is_matched(sample)

        assert is_correct, '%s is not correct, required %s' % (sample,
status)
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