How do I stop Ruff from formatting a block of code?

Wrap the block in `# fmt: off` and `# fmt: on` comments. The formatter leaves every line between them exactly as written and resumes formatting after the `# fmt: on`. These are the same pragma comments Black uses, so they carry over from a Black setup unchanged.

What is the difference between

`# fmt: skip` suppresses formatting for the single statement it ends, so it preserves deliberate alignment on one line. `# fmt: off` opens a range that stays unformatted until a matching `# fmt: on`, so it covers many statements. Use `# fmt: skip` for one line and `# fmt: off`/`# fmt: on` for a block.

No. `# fmt: off`, `# fmt: on`, and `# fmt: skip` control only the formatter (`ruff format`). The linter (`ruff check`) ignores them, so an unused import inside a `# fmt: off` block still reports F401. To silence lint rules, use `# noqa` for one line or `# ruff: disable[CODE]` / `# ruff: enable[CODE]` for a block.

Why does Ruff report RUF028 on my

RUF028 (invalid-formatter-suppression-comment) fires when a suppression comment sits where it cannot take effect, such as a `# fmt: skip` inside a list or other expression. `# fmt: skip` attaches to a whole statement, not an item inside one. Move the comment to the end of the statement, or RUF028 flags it as ineffective.

How to Disable the Ruff Formatter for a Block of Code

by Tim Hopper · Markdown

Ruff

Ruff’s formatter collapses extra whitespace, so a hand-aligned matrix or a column-formatted data table comes back as a single dense line after ruff format. The # fmt: off and # fmt: skip pragma comments tell the formatter to leave a region alone, exactly as Black does.

These comments control the formatter only. To stop the linter from reporting a rule, see how to disable Ruff rules for a block of code.

Wrap the Block in fmt: off and fmt: on

Put # fmt: off on its own line before the block and # fmt: on after it. The formatter preserves every line in between.

# fmt: off
ROTATION = [
    1,  0,  0,
    0,  1,  0,
    0,  0,  1,
]
# fmt: on

Confirm the block survives a format pass:

uv run ruff format --check --diff .

The aligned matrix is left untouched. Code outside the # fmt: off/# fmt: on pair is still formatted normally.

Skip a Single Statement with fmt: skip

For one line, end the statement with # fmt: skip. The formatter leaves that statement’s spacing as written.

grid = [1,  2,  3,  4]  # fmt: skip

# fmt: skip attaches to a whole statement, including a decorator, a function or class definition, or a case header. It cannot suppress one item inside a list or expression.

Keep Suppression Comments Where They Work

# fmt: off and # fmt: on are enforced at the statement level, so placing either mid-expression does nothing. A # fmt: skip inside a list or argument has no effect either.

Ruff flags these dead comments with RUF028 (invalid-formatter-suppression-comment):

values = [
    1, 2, 3,  # fmt: skip  -> RUF028: this comment cannot take effect here
]

Keep RUF028 enabled so a misplaced pragma surfaces in ruff check instead of silently letting the formatter rewrite code you meant to protect.

Map yapf Comments to Ruff

Projects migrating from yapf can leave their # yapf: disable and # yapf: enable comments in place. Ruff treats them as equivalent to # fmt: off and # fmt: on.

Learn More

Last updated on June 24, 2026

How to Disable Ruff Rules for a Block of Code How to distribute internal Python CLI tools with uv

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