Behavior change: Changed type inference logic for binary expressions of the form x or [] so [] uses the type of x to inform its type.
Bug Fix: Fixed bug in the way a specialized variadic type alias is printed (for error messages, hover text, etc.).
Enhancement: Added support for subscript index lists that contain a trailing comma (e.g. a[0,]). The subscript in this case is a tuple and is not valid for most objects, so it should generate an error.
Enhancement: Improved parse error recovery for empty subscripts (e.g. a[]). Started to add support for PEP 637.
Enhancement: Improved consistency of error messages.
New Feature: Added support for PEP 637 (keyword and unpacked arguments in subscripts). This PEP is still in the draft phase and may change before being finalized.
New Feature: Added a way for the "verifytypes" feature to ignore partially-unknown types imported from external packages. To use this feature, append a "!" to the end of the package name provided after the "--verifytypes" option.