If flake8 is installed, pylint isn't ran.

[sontek]

Flake8 doesn't run pylint, so it would be nice to continue getting pylint errors even if flake8 is installed.

[swsnr]

Either customize flycheck-checkers to move the pylint before flake8, or explicitly select Pylint with C-c ! s (flycheck-select-checker).

Section Syntax Checker Selection the Flycheck manual explains the details of syntax checker selection. Be sure to read it.

[sontek]

@lunaryorn The problem isn't the order, I don't mind if I get the pep8 error before the pylint error, but if I have flake8 installed I never get alerts for pylint problems, even if I've fixed all the pep8 issues.

[sontek]

Ahh, just re-read the docs. So we can only ever run 1 syntax checker?

[swsnr]

@sontek Yes, currently Flycheck uses only one Python syntax checker at a time, that is either Flake8, or Pylint. So if Flake8 is present, it will by default never use Pylint. I have no plans to change that.

Flake8 and Pylint do not complement each other. They are intended to be used exclusively. Both check for the same kinds of errors, including PEP 8 violations and code errors. Note that Flake8 checks for more than just PEP 8 violations.

[sontek]

@lunaryorn Sorry, started creating a more specific ticket now that I understood the problem, here: https://github.com/lunaryorn/flycheck/issues/186

Flake8 and Pylint are complimentary. I use them together and vim and catch a lot more than using them individually.

[sontek]

@lunaryorn Whats the best way to tell it to only use pylint if I don't want to customize the plugin itself?

[swsnr]

@sontek Well, as said, select it manually, or change flycheck-checkers in your init.el, e.g. with the following code:

(eval-after-load 'flycheck (cons 'python-pylint (delq 'python-pylint flycheck-checkers)))

Or force Pylint in a mode hook:

(add-hook 'python-mode-hook #'(lambda () (setq flycheck-checker 'python-pylint)))

Note the difference of flycheck-checker versus flycheck-checkers.

[sontek]

I solved this my re-introducing flymake into my init.el, so I have flymake run flake8 and flycheck run pylint

[swsnr]

@sontek I am pretty sure, it would have been easier to just copy the flake8 definition from flycheck.el to your init.el, and add a :next-checkers line that invokes python-pylint.

[choppsv1]

I have a script called pycheckers that runs both, the person claiming this isn't useful must not have tried using both at once for any amount of time. They do overlap but also catch different problems as well. If there's an easier way than definining my own checker and running a script I sure would appreciate it. :)

[mmcnl]

Hi @choppsv1, your pycheckers script sounds very useful. Would you mind sharing any of it?

[choppsv1]

@mmcnl sure, although I ended up doing as @lunaryorn suggested and copying the flake8 definition and creating a new one that chained pylint. Here's the code for that if you'd prefer to use it instead (I suggest doing this btw):

        (defun fix-flake8 (errors)
          (let ((errors (flycheck-sanitize-errors errors)))
            (seq-do #'flycheck-flake8-fix-error-level errors)
            errors))

        (flycheck-define-checker python-flake8-chain
          "A Python syntax and style checker using flake8"
          :command ("flake8"
                     "--format=default"
                     (config-file "--config" flycheck-flake8rc)
                     (option "--max-complexity" flycheck-flake8-maximum-complexity nil
                       flycheck-option-int)
                     (option "--max-line-length" flycheck-flake8-maximum-line-length nil
                       flycheck-option-int)
                     "-")
          :standard-input t
          :error-filter fix-flake8
          :error-patterns
          ((warning line-start
             "stdin:" line ":" (optional column ":") " "
             (id (one-or-more (any alpha)) (one-or-more digit)) " "
             (message (one-or-more not-newline))
             line-end))
          :next-checkers ((t . python-pylint))
          :modes python-mode)

        ;; replace flake8 with new chaining one from above
        (setq flycheck-checkers (cons 'python-flake8-chain (delq 'python-flake8 flycheck-checkers)))

here's the pycheckers.sh script if you want to use that somewhere else (I'd suggest you don't use it in emacs since you still would have do define a new flycheck checker to call it which is the same amount of work as copying the elisp above which bypasses the need for pycheckers...)

pycheckers.sh:

#!/bin/bash 
args=`getopt r:8: $*`
if [ $? != 0 ]; then
    echo 'Usage: ...'
    exit 2
fi
set -- $args
for i; do
    case "$i"
    in
        -r)
            lintconf="$2"; shift;
            shift;;
        -8)
            flakeconf="$2"; shift;
            shift;;
    esac
done
if [[ $flakeconf  ]]; then
    flakeconf=" --config=$flakeconf "
fi
if [[ $lintconf  ]]; then
    lintconf=" --rcfile=$lintconf "
fi
flake8 $flakeconf "$2"
pylint $lintconf -r n --msg-template='{path}:{line}:{column}: {msg_id} {msg}' "$2"

[choppsv1]

@lunaryorn any chance of adding the ability to add chaining to a checker "after the fact" so that instead of having to redefine flake8 checker one could just modify it to be chainging?