Revision history

List of major changes (the Mypy Blog contains more detailed release notes):

• June 2018

  • Publish mypy version 0.610 on PyPI.
    • Major overhaul of documentation.
    • Add the dmypy run command to the daemon.
    • Partially revert the prior changes to section pattern semantics in configuration files (docs and more docs).

• May 2018

  • Publish mypy version 0.600 on PyPI.
    • Enable strict optional checking by default.
    • Document disabling strict optional checking.
    • Add Mypy daemon (mypy server).
    • Add Using a remote cache to speed up mypy runs.
    • Support user-specific configuration file (docs).
    • Changes to section pattern semantics in configuration files (docs and more docs).

• April 2018

  • Publish mypy version 0.590 on PyPI.
    • Document PEP 561 support.
    • Made incremental mode the default.
    • Document --always-true and --always-false (docs).
    • Document follow_imports_for_stubs (docs).
    • Add coroutines to Python 3 cheat sheet.
    • Add None return/strict-optional to common issues.
    • Clarify that SupportsInt etc. don’t support arithmetic operations (see docs).

• March 2018

  • Publish mypy version 0.580 on PyPI.
    • Allow specifying multiple packages on the command line with -p and -m flags.
  • Publish mypy version 0.570 on PyPI.
    • Add support for The attrs package.

• December 2017

  • Publish mypy version 0.560 on PyPI.
    • Various types in typing that used to be ABCs are now protocols and support structural subtyping.
    • Explain how to silence invalid complaints by linters about unused imports due to type comments.

• November 2017

  • Publish mypy version 0.550 on PyPI.
    • Running mypy now requires Python 3.4 or higher. However Python 3.3 is still valid for the target of the analysis (i.e. the --python-version flag).
    • Split --disallow-any flag into separate boolean flags.
    • The --old-html-report flag was removed.

• October 2017

  • Publish mypy version 0.540 on PyPI.
  • Publish mypy version 0.530 on PyPI.

• August-September 2017

  • Add Protocols and structural subtyping.
  • Other updates to The mypy command line:
    • Add --warn-unused-configs.
    • Add --disallow-untyped-decorators.
    • Add --disallow-incomplete-defs.

• July 2017

  • Publish mypy version 0.521 on PyPI.
  • Publish mypy version 0.520 on PyPI.
  • Add fine-grained control of Any types.
  • Add TypedDict.
  • Other updates to The mypy command line:
    • Add --no-implicit-optional.
    • Add --shadow-file.
    • Add --no-incremental.

• May 2017

  • Publish mypy version 0.510 on PyPI.
  • Remove option --no-fast-parser.
  • Deprecate option --strict-boolean.
  • Drop support for Python 3.2 as type checking target.
  • Add support for overloaded functions with implementations.
  • Add Extended Callable types.
  • Add Asynchronous generators (PEP 525) and comprehensions (PEP 530).
  • Add ClassVar.
  • Add quick mode.

• March 2017

  • Publish mypy version 0.500 on PyPI.
  • Add The NoReturn type.
  • Add Defining sub-classes of generic classes.
  • Add Variance of generic types.
  • Add Invariance vs covariance.
  • Updates to New features in Python 3.6.
  • Updates to Integrating mypy into another Python application.
  • Updates to The mypy command line:
    • Add option --warn-return-any.
    • Add option --strict-boolean.
    • Add option --strict.
  • Updates to The mypy configuration file:
    • warn_no_return is on by default.
    • Read settings from setup.cfg if mypy.ini does not exist.
    • Add option warn_return_any.
    • Add option strict_boolean.

• January 2017

  • Publish mypy version 0.470 on PyPI.
  • Change package name from mypy-lang to mypy.
  • Add Integrating mypy into another Python application.
  • Add Type hints cheat sheet (Python 3).
  • Major update to How imports are found.
  • Add –ignore-missing-imports.
  • Updates to The mypy configuration file.
  • Document underscore support in numeric literals.
  • Document that arguments prefixed with __ are positional-only.
  • Document that --hide-error-context is now on by default, and there is a new flag --show-error-context.
  • Add ignore_errors to Per-module flags.

• November 2016

  • Publish mypy-lang version 0.4.6 on PyPI.
  • Add Getting started.
  • Add Generic methods and generic self (experimental).
  • Add Declaring decorators.
  • Discuss generic type aliases in Type aliases.
  • Discuss Python 3.6 named tuple syntax in Named tuples.
  • Updates to Common issues and solutions.
  • Updates to New features in Python 3.6.
  • Updates to The mypy command line:
    • --custom-typeshed-dir
    • --junit-xml
    • --find-occurrences
    • --cobertura-xml-report
    • --warn-no-return
  • Updates to The mypy configuration file:
    • Sections with fnmatch patterns now use module name patterns (previously they were path patterns).
    • Added custom_typeshed_dir, mypy_path and show_column_numbers.
  • Mention the magic MYPY constant in Import cycles.

• October 2016

  • Publish mypy-lang version 0.4.5 on PyPI.
  • Add New features in Python 3.6.
  • Add The mypy configuration file.
  • Updates to The mypy command line: --strict-optional-white-list, --disallow-subclassing-any, --config-file, @flagfile, --hide-error-context (replaces --suppress-error-context), --show-column-numbers and --scripts-are-modules.
  • Mention typing.TYPE_CHECKING in Import cycles.

• August 2016

  • Publish mypy-lang version 0.4.4 on PyPI.
  • Add NewTypes.
  • Add Typing async/await.
  • Add Text and AnyStr.
  • Add Python version and system platform checks.

• July 2016

  • Publish mypy-lang version 0.4.3 on PyPI.
  • Add strict optional checking.
  • Add Multi-line Python 2 function annotations.

• June 2016

  • Publish mypy-lang version 0.4.2 on PyPI.
  • Add The type of class objects.
  • Add Type hints cheat sheet (Python 2).
  • Add Displaying the type of an expression.

• May 2016

  • Publish mypy-lang version 0.4 on PyPI.
  • Add Type variables with upper bounds.
  • Document The mypy command line.

• Feb 2016

  • Publish mypy-lang version 0.3.1 on PyPI.
  • Document Python 2 support.

• Nov 2015

  Add Library stubs and typeshed.

• Jun 2015

  Remove Undefined and Dynamic, as they are not in PEP 484.

• Apr 2015

  Publish mypy-lang version 0.2.0 on PyPI.

• Mar 2015

  Update documentation to reflect PEP 484:

  • Add Named tuples and Optional types.
  • Do not mention type application syntax (for example, List[int]()), as it’s no longer supported, due to PEP 484 compatibility.
  • Rename typevar to TypeVar.
  • Document # type: ignore which allows locally ignoring spurious errors (Spurious errors and locally silencing the checker).
  • No longer mention Any(x) as a valid cast, as it will be phased out soon.
  • Mention the new .pyi stub file extension. Stubs can live in the same directory as the rest of the program.

• Jan 2015

  Mypy moves closer to PEP 484:

  • Add Type aliases.
  • Update discussion of overloading – it’s now only supported in stubs.
  • Rename Function[...] to Callable[...].

• Dec 2014

  Publish mypy version 0.1.0 on PyPI.

• Oct 2014

  Major restructuring. Split the HTML documentation into multiple pages.

• Sep 2014

  Migrated docs to Sphinx.

• Aug 2014

  Don’t discuss native semantics. There is only Python semantics.

• Jul 2013

  Rewrite to use new syntax. Shift focus to discussing Python semantics. Add more content, including short discussions of Generic functions and Union types.