How to enable inline syntax errors/warnings highlighting in Atom

Solution 1:

First you need to decide on which linter you want to use, e.g. flake8 or pycodestyle. The process is the same for either choice, let's use flake8 as an example.

1. Make sure flake8 is installed on your system (see documentation). This will be used by the linter package we install in step 3.
2. Install the basic linter provider for Atom. This is a requirement by the linter package in the next step.
3. Install linter-flake8

While this example serves well to install individual linters, there are–of course–many alternatives to choose from. Since this is a matter of preference, you search what other options are available.

Lastly, take note that many linter packages can be further customized through package settings. Refer to their README for details.