Inline-disable pylint based on logged messages.

inline_disable_pylint.py

"""Inline-disable pylint based on logged messages.

Parses pylint log and adds "# pylint: disable=<msg>, <msg>, .." inline to all flagged
lines, unless the pylint message is of type ERROR or FATAL.

This is useful, to enable a linter on a legacy code base, without the need to address
all warnings right away.

Issues:
- Messages about empty files, e.g. __init__.py are ignored
- Lines that already have an inline-comment are ignored (a warning is printed to stdout)
- Black autoformatting might move the inline comments in a way that pylint ignores them.
https://black.readthedocs.io/en/stable/faq.html#why-does-my-linter-or-typechecker-complain-after-i-format-my-code


Use this command to get expected log file + format:

    pylint -j 0 \
        --rcfile=pylintrc \
        --output=pylint.log \
        --msg-template="{path}:{line}:{msg_id}:{symbol}:{C}" \
        <PATH>
"""

# Group pylint messages by module path and line number
with open("pylint.log") as pylint_log_fp:

    modules = {}
    for line in pylint_log_fp:

        try:
            path, line_number, msg_id, symbol, category = line.rstrip().split(
                ":"
            )
        except ValueError:
            continue

        line_number = int(line_number)

        # Skip ERROR and FATAL type pylint messages. They should not be ignored!!
        if category in ["E", "F"]:
            print(f"FIX:{path}:{line_number}:{symbol}")
            continue

        if path not in modules:
            modules[path] = {}

        if line_number not in modules[path]:
            modules[path][line_number] = []

        modules[path][line_number].append(symbol)


# Add inline comments to disable pylint message types
for module_path, line_numbers in modules.items():

    new = ""
    with open(module_path) as module_fp:
        for line_number, line in enumerate(module_fp, 1):
            message_list = line_numbers.get(line_number)

            if message_list is None:
                new += line
                continue

            messages = ",".join(message_list)
            comment = f"# pylint: disable={messages}"

            if "#" in line:
                print(f"FIX:{module_path}:{line_number}:{messages}")
                new += line
                continue

            new += line.rstrip() + f" {comment}\n"

    with open(module_path, "w") as module_fp:
        module_fp.write(new)