https://doc.rust-lang.org/beta/nightly-rustc/rustc_errors/codes/constant.E0603.html
E0603 in rustc_errors::codes - Rust
API documentation for the Rust `E0603` constant in crate `rustc_errors`.
rustcerrorscodes
https://pylint.readthedocs.io/en/stable/user_guide/messages/error/undefined-all-variable.html
undefined-all-variable / E0603 - Pylint 4.0.5 documentation
undefinedvariablepylintdocumentation