With Python Black (prior to 19.2b), how to skip normalizing underscores in numeric literals?

Question

I am using Black with Python 3.7 (in VS Code).

When I format my code, the numeric literals are normalized with the underscore (e.g. 1562202 => 1_562_202).

How to use Black Formatting without formatting by using the underscore?

NOTE From black version 19.2b, this question becomes obsolete.

@U9-Forward No, it's a numeric literal allowed in Python 3.7. — Jean-Francois T., Dec 26 '18 at 03:08
Numeric underscore normalization was removed in [black 19.2b0](https://github.com/ambv/black#192b0) — Boris Verkhovskiy, Feb 11 '19 at 13:17

score 5 · Answer 1 · answered Dec 26 '18 at 03:05

To avoid formatting literals, use black --skip-numeric-underscore-normalization or the short flag, black -N

You can make this a permanent change by modifying your pyproject.toml file:

[tool.black]
skip-numeric-underscore-normalization = true

score 0 · Accepted Answer · answered Dec 26 '18 at 03:07

As mentionned in the official documentation of Black, the following option can skip adding underscore in numeric literals:

-N, --skip-numeric-underscore-normalization Don't normalize underscores in numeric literals.

In VS Code, just add the following option in your User Settings JSON file:

"python.formatting.blackArgs": ["--skip-numeric-underscore-normalization"]

2 Answers2