X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/04518c38c945ecf3c15765b71642112495cade8d..d249f2d8380893f051b63140e3768cef599f49f3:/docs/faq.md?ds=sidebyside diff --git a/docs/faq.md b/docs/faq.md index 46e4598..d7e6a16 100644 --- a/docs/faq.md +++ b/docs/faq.md @@ -21,7 +21,8 @@ _Black_ is still in [beta](index.rst), some edges are still a bit rough. To comb issues, the equivalence of code after formatting is [checked](the_black_code_style/current_style.md#ast-before-and-after-formatting) with limited special cases where the code is allowed to differ. If issues are found, an error -is raised and the file is left untouched. +is raised and the file is left untouched. Magical comments that influence linters and +other tools, such as `# noqa`, may be moved by _Black_. See below for more details. ## How stable is Black's style? @@ -36,6 +37,29 @@ Most likely because it is ignored in `.gitignore` or excluded with configuration [file collection and discovery](usage_and_configuration/file_collection_and_discovery.md) for details. +## Why is my Jupyter Notebook cell not formatted? + +_Black_ is timid about formatting Jupyter Notebooks. Cells containing any of the +following will not be formatted: + +- automagics (e.g. `pip install black`) +- multiline magics, e.g.: + + ```python + %timeit f(1, \ + 2, \ + 3) + ``` + +- code which `IPython`'s `TransformerManager` would transform magics into, e.g.: + + ```python + get_ipython().system('ls') + ``` + +- invalid syntax, as it can't be safely distinguished from automagics in the absense of + a running `IPython` kernel. + ## Why are Flake8's E203 and W503 violated? Because they go against PEP 8. E203 falsely triggers on list @@ -50,3 +74,11 @@ For formatting, yes! [Install](getting_started.md#installation) with the `python to format Python 2 files too! There are no current plans to drop support, but most likely it is bound to happen. Sometime. Eventually. In terms of running _Black_ though, Python 3.6 or newer is required. + +## Why does my linter or typechecker complain after I format my code? + +Some linters and other tools use magical comments (e.g., `# noqa`, `# type: ignore`) to +influence their behavior. While Black does its best to recognize such comments and leave +them in the right place, this detection is not and cannot be perfect. Therefore, you'll +sometimes have to manually move these comments to the right place after you format your +codebase with _Black_.