gopy/README.md

gopy
====

`gopy` generates (and compiles) a `CPython` extension module from a `go` package.

## Installation

```sh
$ go get github.com/go-python/gopy
```

## Documentation

Documentation is available on [godoc](https://godoc.org):
 https://godoc.org/github.com/go-python/gopy
 
or directly from the command-line prompt:

```sh
$ gopy help
gopy - 

Commands:

    bind        generate and compile (C)Python language bindings for Go
    gen         generate (C)Python language bindings for Go

Use "gopy help <command>" for more information about a command.


$ gopy help gen
Usage: gopy gen <go-package-name>

gen generates (C)Python language bindings for a Go package.

ex:
 $ gopy gen [options] <go-package-name>
 $ gopy gen github.com/go-python/gopy/_examples/hi

Options:
  -lang="python": target language for bindings
  -output="": output directory for bindings


$ gopy help bind
Usage: gopy bind <go-package-name>

bind generates and compiles (C)Python language bindings for a Go package.

ex:
 $ gopy bind [options] <go-package-name>
 $ gopy bind github.com/go-python/gopy/_examples/hi

Options:
  -output="": output directory for bindings

```


## Examples

```sh
$ gopy bind -output=out github.com/go-python/gopy/_examples/hi
$ ls out
hi.so

$ cd out
$ python2
>>> import hi
>>> dir(hi)
['Add', 'Concat', 'Hello', 'Hi', 'NewPerson', 'Person', '__doc__', '__file__', '__name__', '__package__']

>>> hi.Hello("you")
hello you from go

```

You can also run:

```sh
go test -v -run=TestBind
=== RUN   TestBind
processing "Add"...
processing "Concat"...
processing "Hello"...
processing "Hi"...
processing "NewPerson"...
processing "Person"...
processing "Add"...
processing "Concat"...
processing "Hello"...
processing "Hi"...
processing "NewPerson"...
processing "Person"...
github.com/go-python/gopy/_examples/hi
_/home/binet/dev/go/root/tmp/gopy-431003574
--- hi.Hi()...
hi from go
--- hi.Hello('you')...
hello you from go
--- hi.Add(1, 41)...
42
--- hi.Concat('4', '2')...
42
--- doc(hi.Person):
Person is a simple struct

--- p = hi.Person()...
<hi.Person object at 0x7fc46cc330f0>
['Age', 'Name', '__class__', '__delattr__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__']
--- p.Name: None
--- p.Age: None
--- doc(p):
Person is a simple struct

--- PASS: TestBind (2.13s)
PASS
ok  	github.com/go-python/gopy	2.135s
```

## Limitations

- wrap `go` structs into `python` classes
- better pythonization: turn `go` `errors` into `python` exceptions
- only `python-2` supported for now