Mailman 3 May 2016 - code-quality

pyflakes-study group and code
by Edward K. Ream 03 Jun '16

03 Jun '16

Hello all, I recently integrated pyflakes into Leo <http://leoeditor.com/> and am awed by its speed and elegance. Its simplicity is pure genius. A few days ago I set up the pyflakes-study google group <https://groups.google.com/forum/#!forum/pyflakes-study> and corresponding github repo <https://github.com/edreamleo/pyflakes-study> and have been happily playing around with the pyflakes code ever since. To properly see what I have done you will have to look at the .leo file with Leo. To paraphrase Richard Feynman, that which I cannot alter I do not understand. By this criterion I now understand almost every line of pyflakes. Hehe. It's possible to speed up pyflakes by at least 10% by using a less elegant traversal scheme, as describe here <https://groups.google.com/forum/#!topic/pyflakes-study/amxtB0MKOGI>. Not sure whether you would be interested--there are some drawbacks. It's also possible to speed up pyflakes by an additional 5% merely by removing the scope property, as described in today's post <https://groups.google.com/forum/#!topic/pyflakes-study/9WoO9shG5fk>. This post also describes a buglet in pyflakes and its fix. Most of today's post is geared toward a new tool I am considering. This would compare name conventions with actual usage. The first phase might be a scope resolver, using a simplified version of the pyflakes code. The second phase will have to do a whole lot more with Ast.Attribute :-) You might call the new tool a follow up to my make-stub-files project <https://groups.google.com/forum/#!topic/python-static-type-checking/n68MH1x…>, with corresponding github repo <https://github.com/edreamleo/make-stub-files>. I announced make-stub-files in my largely unsuccessful python-static-typechecking <https://groups.google.com/forum/#%21forum/python-static-type-checking> group. Boy, am I happy mypy <http://mypy-lang.org/> is doing the heavy lifting. I would appreciate any comments, suggestions and corrections you might have. Edward ------------------------------------------------------------------------------------------ Edward K. Ream: edreamleo(a)gmail.com Leo: http://leoeditor.com/ ------------------------------------------------------------------------------------------

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Patch to expose path of rcfile
by Tim Stumbaugh 02 Jun '16

02 Jun '16

Hello, We are in the early phases of rolling out pylint to our Python application. We have a particularly strange setup where we use __path__ in a number of "virtual packages" in order to set the correct location of the real package. Activating astroid's behavior which scans sys.path (the from pkgutil import extend_path trick) in combination with manipulating sys.path in an init-hook works great and allows pylint to see the package the same way the interpreter does. However, figuring out the correct path to insert onto sys.path is unfortunately not trivial, since we support running pylint as part of our pre-commit review tool, which runs it in a different directory but passes --rcfile on the command-line. In order to get the correct directory, we need to have the path of the current rcfile (be it one that came from config.find_pylintrc or one that came from --rcfile). Unfortunately, it seems that config.PYLINTRC does not get updated to include the path of the file if --rcfile is given. Our current solution to this problem is to use inspect within the init-hook to step back up to the frame of Run and look at the config_file member of the linter: > init-hook=import inspect; > sys.path.append(os.path.dirname(inspect.stack()[2][0].f_locals["linter"].config_file)) However, since this essentially couples us to the internals of pylint, it would be nice to have something a little less invasive. I prepared a patch to pylint/lint.py that would set config.PYLINTRC in cb_set_rcfile. That allows the init-hook above to be replaced by: > init-hook=sys.path.append(os.path.dirname(config.PYLINTRC)) And preserve the same behavior. My question is, would this be a change that the project is interested in? I didn't just want to send a pull request out of the blue, since the actual change is trivial. Is there some better way to accomplish what I am trying to do? Thanks for your consideration, tjs -- Tim Stumbaugh Operations Hudson River Trading

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[Social] Who is going to PyCon (US)?
by Ian Cordasco 31 May '16

31 May '16

Hey everyone, Ian Lee and I were chatting privately and are planning on meeting up at PyCon in Portland. We thought it would probably be a good idea to get a group together for lunch or dinner or something. So, who's going to be there and who wants to plan to meet-up? We don't have to focus our gathering around food, we can plan for a Birds of a Feather meeting instead if that's desirable. We can chat about specific projects, the PyCQA, this list, or whatever. Cheers, Ian

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Flake8 pre-commit hook in virtualenvs and vagrant
by Brent O'Connor 26 May '16

26 May '16

If you use a tool like SourceTree, having the first line as `#!/usr/bin/env python` in your pre-commit script will mean that it doesn’t work if you’re using a virtualenv. Instead you need to change the first like to something like `#!/usr/local/virtualenvs/myproject/bin/python`. I actually document that in the docs to my Django Base Site (http://django-base-site.readthedocs.io/en/latest/pre-commit-hook.html). So the question is, should that be added to the flake8 documentation (http://flake8.readthedocs.io/en/latest/vcs.html)? Also, has anyone found a way to make tools like SourceTree work on your host system, when your project is using a virtualenv under a vagrant VM? If so, could this get added to the docs as well? - Brent

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Pylint failing with tox
by Ahirnish Pareek 25 May '16

25 May '16

Hi Devs, I am running already existing tests before adding one of my own with tox and the test is failing along with pylint which runs after the tests. Pylint is failing because it expects type Node and getting type Str at the affected location. I have changed the /pylint/tox.ini file to run only /pylint/pylint/test/test_self.py - commands = python -Wi -m unittest discover -s {envsitepackagesdir}/pylint/test/ -p {posargs:**test_self**}.py Traceback: Traceback (most recent call last): File "pylint/bin/pylint", line 11, in <module> sys.exit(run_pylint()) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/__init__.py", line 23, in run_pylint Run(sys.argv[1:]) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/lint.py", line 1313, in __init__ linter.check(args) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/lint.py", line 734, in check self._do_check(files_or_modules) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/lint.py", line 865, in _do_check self.check_astroid_module(ast_node, walker, rawcheckers, tokencheckers) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/lint.py", line 943, in check_astroid_module walker.walk(ast_node) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 940, in walk self.walk(child) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 940, in walk self.walk(child) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 940, in walk self.walk(child) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 940, in walk self.walk(child) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 940, in walk self.walk(child) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/utils.py", line 936, in walk cb(astroid) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint/checkers/base.py", line 1951, in visit_assign if var_type == astroid.YES or var_type.as_string() == 'None': File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/astroid/node_classes.py", line 446, in as_string return as_string.to_code(self) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/astroid/as_string.py", line 37, in __call__ return node.accept(self) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/astroid/node_classes.py", line 230, in accept return func(self) File "/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/astroid/as_string.py", line 297, in visit_list return '[%s]' % ', '.join([child.accept(self) for child in node.elts]) AttributeError: 'str' object has no attribute 'accept' ERROR: InvocationError: '/Users/ahirnish/pylint_patch/pylint/.tox/pylint/bin/pylint -rn --rcfile=/Users/ahirnish/pylint_patch/pylint/pylintrc /Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint' After initial debugging, I could see that node.elts is a list of strings = [ '-rn', '--rcfile=/Users/ahirnish/pylint_patch/pylint/pylintrc', '/Users/ahirnish/pylint_patch/pylint/.tox/pylint/lib/python2.7/site-packages/pylint' ] But I cant figure out how command line arguments got introduced in the chain. Any help here would be great. Thanks in advance. -- Regards, Ahirnish

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Nested loop with same control variable: no warning?
by Dan Stromberg 23 May '16

23 May '16

Why doesn't the following produce a pylint warning? for counter in range(2): for counter in range(3): print(counter) Note that we've used "counter" twice. Thanks! -- Dan Stromberg

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Proper integration of Pylint into Jenkins Violations plugin on Windows
by Michal Svoboda 05 May '16

05 May '16

Hello, I would like to ask you for help with integration of Pylint into Jenkins Violations plugin on Windows. What I have: - During Jenkins job Pylint is called (“pylint %listOfPackages% | tee pylint.out”) - The example of the “pylint.out” is in the attachment - Following picture depicts the Jenkins job configuration, the Report Violations part: [cid:image002.png@01D1A6CE.58C22F90] What I see after job run: - The graphical Pylint output is always empty – see following picture: [cid:image003.png@01D1A6CE.58C22F90] - The “violations.xml” generated in “<Jenkins root>\jobs\<job name>\builds\<build>\violations\” is (almost) empty too: <?xml version="1.0"?> <violations><file:///C:\Program%20Files%20(x86)\Jenkins\jobs\rf_lib-pte-generic_COMMIT\builds\72\violations\violations.xml><type name="pylint"> </type></violations> What should I do to make Jenkins to fill “violations.xml” and thus graphical Pylint output be filled? Thanks for your help. Michal Svoboda

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