Python C extension Assistant generates Python C code in order to aid in extension development
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PyCA -- Python C extension Assistant

Generates Python C API code in order to aid in C extension development.

Copyright (c) 2009 Rasmus Andersson. Licensed under MIT.


General usage:

Usage: pyca [options] COMMAND [ARGS]

  help        Display help about a certain command or pyca itself.
  init        Create and initialize a new project.
  show        Generate and display Python C code.

  --version    show program's version number and exit
  -h, --help   show this help message and exit
  -q, --quiet  Don't print status messages to stdout


Usage: pyca init [options] <name> [<path>]

Create and initialize a new project.

If <path> is not specified it defaults to './' + <name>

  -h, --help            show this help message and exit
  --dry-run             Simulate but don't actually do anything.
  -t <title>, --title=<title>
                        Human-readable title of project. Defaults to <name>.
  -a <author>, --author=<author>
                        Author of the project. If not set, author will be
  -u <url>, --url=<url>
                        URL pointing to more information.
  -y <year>, --year=<year>
                        Copyright year. Defaults to 2009
  -l <license>, --license=<license>
                        Software license. Defaults to 'mit' (for a list of
                        available licenses, see contents of directory


Usage: pyca show <signature>
       pyca show <type> <signature> [<type> <signature> ...]

Generate and display Python C code.


  Show a function:
    pyca show 'mymod.myfunc(myarg1, myarg2)'

  Show a function (with type hinting):
    pyca show 'mymod.myfunc(i size, s message = "hello")'

  Show a method and a function:
    pyca show meth 'mymod.MyClass.mymeth(i size, s message = "hello")'\
              func 'mymod.myfunc(i size, s message = "hello")'

  Show a static method:
    pyca show smeth 'mymod.MyClass.mymeth(i size, s message = "hello")'

Type hinting is (optionally) performed by adding a PyArg_Parse symbol in front
of arguments.

  -h, --help  show this help message and exit


Creating a new project

$ ./pyca init fluffy_hamster
Creating new project 'fluffy_hamster' in '/Users/rasmus/src/pyca/fluffy_hamster'
  PROJECT_AUTHOR         => 'Rasmus Andersson <>'
  PROJECT_AUTHOR_NAME    => 'Rasmus Andersson'
  PROJECT_MODULE         => 'fluffy_hamster'
  PROJECT_TITLE          => 'fluffy_hamster'
  PROJECT_URL            => ''
  PROJECT_YEAR           => '2009'
dir     fluffy_hamster
cpy     fluffy_hamster/.gitignore
cpy     fluffy_hamster/CHANGELOG.rst
dir     fluffy_hamster/docs
dir     fluffy_hamster/docs/source
dir     fluffy_hamster/docs/source/_static
cpy     fluffy_hamster/docs/source/_static/info.png
cpy     fluffy_hamster/docs/source/_static/jump.png
cpy     fluffy_hamster/docs/source/_static/screen.css
dir     fluffy_hamster/docs/source/_templates
sub 2   fluffy_hamster/docs/source/_templates/layout.html
sub 4   fluffy_hamster/docs/source/
sub 1   fluffy_hamster/docs/source/index.rst
dir     fluffy_hamster/docs/source/library
sub 1   fluffy_hamster/docs/source/library/index.rst
sub 3   fluffy_hamster/docs/source/library/fluffy_hamster.rst
dir     fluffy_hamster/lib
dir     fluffy_hamster/lib/fluffy_hamster
sub 3   fluffy_hamster/lib/fluffy_hamster/
cpy     fluffy_hamster/lib/fluffy_hamster/
dir     fluffy_hamster/lib/fluffy_hamster/test
sub 2   fluffy_hamster/lib/fluffy_hamster/test/
cpy     fluffy_hamster/
sub 1   fluffy_hamster/README.rst
sub 10  fluffy_hamster/
dir     fluffy_hamster/src
sub 19  fluffy_hamster/src/__init__.c
sub 3   fluffy_hamster/src/__init__.h
sub 4   fluffy_hamster/src/_macros.h
cpy     fluffy_hamster/src/util.c
sub 2   fluffy_hamster/src/util.h
sub 1   fluffy_hamster/test-working
sub 2   fluffy_hamster/LICENSE

$ cd fluffy_hamster/
$ ./test-working
./test-working: Building and testing with Python 2.4

Ran 0 tests in 0.000s

./test-working: Building and testing with Python 2.5

Ran 0 tests in 0.000s

./test-working: Building and testing with Python 2.6

Ran 0 tests in 0.000s

./test-working: Building and testing with Python 3.0

Ran 0 tests in 0.000s


Show generated code

Note that you do not need to have any existing project in order to use the show command, as is simply parses signatures and generates Python C code just-in-time.

$ pyca show meth 'mymod.SomeClass.echo(s msg, i times=3, s# prefix = "")'
> docs/source/mymod.SomeClass.echo.rst:
    .. method:: echo(msg, times=3, prefix="")

> src/mymod_SomeClass.h:
   * @param const char *msg
   * @param int times = 3
   * @param const char *prefix = ""
  PyObject *mymod_SomeClass_echo(PyObject *self, PyObject *args, PyObject *kwargs);

> src/mymod_SomeClass.c:
   * mymod.SomeClass.echo(s msg, i times=3, s# prefix = "")
  PyObject *mymod_SomeClass_echo(PyObject *self, PyObject *args, PyObject *kwargs) {
    const char *msg = NULL;
    int times = 3;
    const char *prefix = "";
    int prefix_length = 0;
    static char *kwlist[] = {"msg", "times", "prefix", NULL};

    /* Parse arguments */
    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s|is#:echo", kwlist,
      &msg, &times, &prefix, &prefix_length))
      return NULL;

    /* TODO: implementation */
    PyErr_SetString(PyExc_NotImplementedError, "mymod.SomeClass.echo");
    return NULL;