Welcome to Typing Specification’s documentation!

Contents:

• Typing Specification
• Basics of the type system
  • The meaning of annotations
  • Type definition syntax
  • Definition of terms
  • Acceptable type hints
  • Non-goals
• Type system features
  • Using None
  • Type aliases
  • Callable
  • Generics
  • User-defined generic types
  • Scoping rules for type variables
  • Instantiating generic classes and type erasure
  • Arbitrary generic types as base classes
  • Abstract generic types
  • Type variables with an upper bound
  • Covariance and contravariance
  • Variance Inference
  • Forward references
  • Union types
  • Support for singleton types in unions
  • The Any type
  • The NoReturn type
  • The Never type
  • The type of class objects
  • Annotating instance and class methods
  • Version and platform checking
  • TYPE_CHECKING
  • ClassVar
  • Protocols
  • Function/method overloading
  • Literal
  • TypedDict
  • Required and NotRequired
  • The final decorator
  • The Final annotation
  • Annotated
  • ParamSpec
  • TypeVarTuple
  • TypeGuard
  • Self
  • The dataclass_transform decorator
  • Unpack
  • @override
  • assert_type()
  • reveal_type()
  • # type: ignore comments
  • cast()
  • NewType
• Interaction with Python features
  • Special cases for subtyping
  • Arbitrary argument lists and default argument values
  • Annotating generator functions and coroutines
  • Compatibility with other uses of function annotations
• Communicating type information
  • Stub files
  • Storing and distributing types for library packages
  • The typing Module
• Syntax alternatives
  • Type comments
  • Type comments on function definitions
  • Positional-only arguments
  • Generics in standard collections
  • Union and Optional
  • Unpack

Indices and tables

• Index

• Module Index

• Search Page