Metadata-Version: 2.0
Name: retype
Version: 17.6.2
Summary: Re-apply types from .pyi stub files to your codebase.
Home-page: https://github.com/ambv/retype
Author: Łukasz Langa
Author-email: lukasz@langa.pl
License: MIT
Keywords: mypy typing typehints type hints pep484 pyi stubs
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Environment :: Console
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3.6
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Classifier: Topic :: Software Development :: Quality Assurance
Requires-Dist: click
Requires-Dist: typed-ast

retype
======

|Build Status|

Re-apply type annotations from .pyi stubs to your codebase.

Usage
-----

::

    retype [OPTIONS] [SRC]...

    Options:
      -p, --pyi-dir DIRECTORY     Where to find .pyi stubs.  [default: types]
      -t, --target-dir DIRECTORY  Where to write annotated sources.  [default: typed-src]
      -i, --incremental           Allow for missing type annotations in both stubs
                                  and the source.
      -q, --quiet                 Don't emit warnings, just errors.
      --hg                        Post-process source files to preserve
                                  implicit byte literals.
      --traceback                 Show a Python traceback on error
      --version                   Show the version and exit.
      --help                      Show this message and exit.

When you run ``retype``, it goes through all files you passed as SRC,
finds the corresponding .pyi files in the ``types/`` directory, and
re-applies typing annotations from .pyi to the sources, using the Python
3 function and variable annotation syntax. The resulting combined
sources are saved in ``typed-src/``.

You can also pass directories as sources, in which case ``retype`` will
look for .py files in them recursively.

It's smart enough to do the following:

-  reapply typing imports
-  reapply function argument annotations
-  reapply function return value annotations
-  reapply method argument and return value annotations
-  reapply function-level variable annotations
-  reapply module-level name annotations
-  reapply module-level type aliases
-  reapply class-level field annotations
-  reapply instance-level field annotations
-  validate existing source annotations against the .pyi file
-  validate source function signatures against the .pyi file
-  read function signature type comments in .pyi files
-  read variable type comments in .pyi files
-  consider existing source type comments as annotations
-  remove duplicate type comments from source when annotations are
   applied
-  normalize remaining type comments in the source to annotations; this
   is done even if the corresponding .pyi file is missing

List of things to be done
-------------------------

-  [ ] add a --backward option to output type comments instead of
   annotations
-  [ ] handle if sys.version\_info and sys.platform checks in stubs

Design principles
-----------------

-  it's okay for a given .pyi file to be incomplete (gradual typing,
   baby!)
-  it's okay for functions and classes to be out of order in .pyi files
   and the source
-  it's an **error** for a function or class to be missing in the source
-  it's an **error** for a function's signature to be incompatible
   between the .pyi file and the source
-  it's an **error** for an annotation in the source to be incompatible
   with the .pyi file

Known limitations
-----------------

-  Line numbers in the annotated source will no longer match original
   source code; this is because re-application of types requires copying
   typing imports and alias definitions from the .pyi file.
-  While formatting of the original source will be preserved, formatting
   of the applied annotations might differ from the formatting in .pyi
   files.
-  The source where type annotations get re-applied cannot use the
   legacy ``print`` statement; that wouldn't work at runtime.
-  Class attribute annotations in ``__init__()`` methods are moved
   verbatim to the respective ``__init__()`` method in the
   implementation. They are never translated into class-level attribute
   annotations, so if that method is missing, the translation will fail.
   Similarly, class-level attribute annotations are never applied to
   ``__init__()`` methods.
-  Forward references in .pyi files will only be properly resolved for
   type aliases and type vars (by inserting them right before they're
   used in the source). Other forms of forward references will not work
   in the source code due to out-of-order class and function
   definitions. Modify your .pyi files to use strings. ``retype`` will
   not automatically discover failing forward references and stringify
   them.
-  Local variable annotations present in the .pyi file are transferred
   to the body level of the given function in the source. In other
   words, if the source defines a variable within a loop or a
   conditional statement branch, ``retype`` will create an value-less
   variable annotation at the beginning of the function. Use a broad
   type and constrain types in relevant code paths using
   ``assert isinstance()`` checks.
-  Because of the above, existing source variable annotations and type
   comments buried in conditionals and loops will not be deduplicated
   (and ``mypy`` will complain that a name was already defined).
-  An async function in the stub will match a regular function of the
   same name in the same scope and vice versa. This is to enable
   annotating async functions spelled with ``@asyncio.coroutine``.

Tests
-----

Just run:

::

    python setup.py test

OMG, this is Python 3 only!
---------------------------

Relax, you can run *retype* **as a tool** perfectly fine under Python
3.6+ even if you want to analyze Python 2 code. This way you'll be able
to parse all of the new syntax supported on Python 3 but also
*effectively all* the Python 2 syntax at the same time.

By making the code exclusively Python 3.6+, I'm able to focus on the
quality of the checks and re-use all the nice features of the new
releases (check out `pathlib <docs.python.org/3/library/pathlib.html>`__
or f-strings) instead of wasting cycles on Unicode compatibility, etc.

Note: to retype modules using f-strings you need to run on Python 3.6.2+
due to `bpo-23894 <http://bugs.python.org/issue23894>`__.

License
-------

MIT

Change Log
----------

17.6.2
~~~~~~

-  bugfix: --incremental didn't work with multiple arguments before

17.6.1
~~~~~~

-  support --incremental stub application (i.e. allow for both stubs and
   the source to be missing annotations for some arguments and/or return
   value)

17.6.0
~~~~~~

-  support async functions

-  support --traceback for getting more information about internal
   errors

17.4.0
~~~~~~

-  first published version

-  date-versioned

Authors
-------

Glued together by `Łukasz Langa <mailto:lukasz@langa.pl>`__.

.. |Build Status| image:: https://travis-ci.org/ambv/retype.svg?branch=master
   :target: https://travis-ci.org/ambv/retype


