I first got into Python in the mid-to-late 1990s. It's so far back that I
think the copy of Programming
Python that I have (sadly in
storage at the moment) might be a first edition. I probably fell out of the
habit of using Python some time in the early 2000s (that was when I met
Ruby). It was only 22 months ago that I started using Python a lot thanks
to a change of
employer.
As you might imagine, much had changed in the 15+ years since I'd last
written a line of Python in anger. So, early on, I made a point of making
Pylint part of my development process. All my
projects have a make lint
make target. All of my projects lint the code
when I push to master
in the company GitLab instance. These days I even
use flycheck to keep me honest as I
write my code; mostly gone are the days where I don't know of problems until
I do a make lint
.
Leaning on Pylint in the early days of my new position made for a great
Python refresher for me. Now, I still lean on it to make sure I don't make
daft mistakes.
But...
Pylint and I don't always agree. And that's fine. For example, I really
can't stand Pylint's approach to whitespace, and that is a hill I'll happily
die on. Ditto the obsession with lines being no more than 80 characters wide
(120 should be fine thanks). As such any project's .pylintrc
has, as a
bare minimum, this:
[FORMAT]
max-line-length=120
[MESSAGES CONTROL]
disable=bad-whitespace
Beyond that though, aside from one or two extras that pertain to particular
projects, I'm happy with what Pylint complains about.
There are exceptions though. There are times, simply due to the nature of
the code involved, that Pylint's insistence on code purity isn't going to
work. That's where I use its inline block disabling
feature.
It's handy and helps keep things clean (I won't deploy code that doesn't
pass 10/10), but there is always this nagging doubt: if I've disabled a
warning in the code, am I ever going to come back and revisit it?
To help me think about coming back to such disables now and again, I thought
it might be interesting to write a tool that'll show which warnings I
disable most. It resulted in this fish
abbr:
abbr -g pylintshame "rg --no-messages \"pylint:disable=\" | awk 'BEGIN{FS=\"disable=\";}{print \$2}' | tr \",\" \"\n\" | sort | uniq -c | sort -hr"
The idea here being that it produces a "Pylint hall of shame", something
like this:
12 wildcard-import
12 unused-wildcard-import
8 no-member
6 invalid-name
5 no-self-use
4 import-outside-toplevel
4 bare-except
2 unused-argument
2 too-many-public-methods
2 too-many-instance-attributes
2 not-callable
2 broad-except
1 wrong-import-position
1 wrong-import-order
1 unused-variable
1 unexpected-keyword-arg
1 too-many-locals
1 arguments-differ
To break the pipeline down:
rg --no-messages "pylint:disable="
First off, I use ripgrep
(if you
don't, you might want to have a good look at it -- I find it amazingly
handy) to find everywhere in the code in and below the current directory
(the --no-messages
switch just stops any file I/O errors that might result
from permission issues -- they're not interesting here) that contains a line
that has a Pylint block disable (if you tend to format yours differently,
you'll need to tweak the regular expression, of course).
I then pipe it through awk
:
awk 'BEGIN{FS="disable=";}{print $2}'
so I can lazily extract everything after the
disable=
.
Next up, because it's a possible list of things that can be disabled, I use
tr
:
to turn any comma-separated list into multiple lines.
Having got to this point, I sort
the list, uniq
the result, while
prepending a count (-c
), and then sort
the result again, in reverse and
sorting the numbers based on how a human would read the result (-hr
).
sort | uniq -c | sort -hr
It's short, sweet and hacky, but does the job quite nicely. From now on, any
time I get curious about which disables I'm leaning on too much, I can use
this to take stock.