When I use cython compile my *.py files to *.so, it looks good and no error occurred. But when I run my project it throw out such error exception: RuntimeError: super(): __class__ cell not found(I'm sure I can run the project from the source code without any problems)
...debuging...
After debugging for a few minutes, I found this ancient issue: https://github.com/cython/cython/issues/1127
My goodness, this bug has not been resolved for more than ten years......
Fortunately, I got a simple solution: roll back the legacy python2 super style
And here comes the problems:
- How to roll back the py2 super style in batches? I have so many *.py files...
- How to warn team members not to use the py3 super style?
...coding...
And here comes the solution:
- Because I am lazy, I wrote a script to help me do this:
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"""Change py3 super style to py2's"""
import re
from pathlib import Path
class_p = re.compile(r'class (?P<class_name>\w+)[\(:]')
def replace(path):
with open(path, 'r') as read_file:
reversed_lines = read_file.readlines()[::-1]
for idx, line in enumerate(reversed_lines[:]):
if 'super().' in line:
print(f'{path}:{len(reversed_lines) - idx}')
cls_str = 'cls' if '__new__' in line else 'self'
for above_line in reversed_lines[idx:]:
if '@classmethod' in line:
cls_str = 'cls'
continue
match = class_p.search(above_line)
if match:
reversed_lines[idx] = line.replace('super().', f'super({match.group("class_name")}, {cls_str}).')
break
with open(path, 'w') as write_file:
write_file.writelines(reversed_lines[::-1])
if __name__ == '__main__':
for file in Path('.').glob('**/*.py'):
if __file__ != file.as_posix():
replace(file)
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- Like most Python projects, we also use pylint to check the code style, I copied the template and wrote a custom checker:
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"""file: py3_style_checker.py"""
import astroid
from pylint import checkers, interfaces
from pylint.checkers import utils
class PY3StyleSupperChecker(checkers.BaseChecker):
__implements__ = (interfaces.IAstroidChecker,)
name = "py3-style-super"
msgs = {
"R0711": (
"Consider using Python 2 style super() within arguments",
"super-without-arguments",
"Emitted when calling the super() builtin with the current class "
"and instance. We need to keep the legacy Python 2 style super to "
"make the Cython compile correct.",
),
}
options = ()
priority = -1
@utils.check_messages(
"super-without-arguments",
)
def visit_call(self, node):
self._check_super_without_arguments(node)
def _check_super_without_arguments(self, node):
if not isinstance(node.func, astroid.Name) or node.func.name != "super":
return
if len(node.args) != 0:
return
self.add_message("super-without-arguments", node=node)
def register(linter):
linter.register_checker(PY3StyleSupperChecker(linter))
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We need to add the checker's parent directory into current PYTHONPATH, and run pylint like this:
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$ pylint --load-plugins=py3_style_checker --disable=all --enable=super-without-arguments <path_to_your_py_file>
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done!
Ref
- How to Write a Checker
- super doesn't work with cpdef methods
# NOTE: I am not responsible for any expired content.
create@2021-07-10T23:11:20+08:00
update@2021-07-10T23:23:59+08:00
comment@https://github.com/ferstar/blog/issues/42