PyBind.rb is a lightweight Ruby - Python binding using ffi
, it aims to create a way to call exsisting Python functions in Ruby. With the power of PyBind.rb, you can use all data-science packages in Python, e.g.: numpy
, pandas
, matplotlib
, and even tensorflow
.
More use-cases can be found in examples
folder.
Add this line to your application's Gemfile:
gem 'pybind'
And then execute:
$ bundle
Or install it yourself as:
$ gem install pybind
Hello world with PyBind.rb
# This program prints Hello, world!
require 'pybind'
# You can eval a string in Python with `PyBind.eval`,
# this is the easiest way to use PyBind.rb
# and this is equivalent to Python built-in `eval` function
PyBind.eval('print("Hello, world!")')
# Or exec a Python file
PyBind.execfile('examples/hello_world.py')
# You can find all Python built-in functions at `PyBind.builtin`
# Note that `PyBind.builtin.print` is a Python function object,
# like a `proc` in Ruby, you need to call it by adding a `.` or `.call`
# if you don't like it, see `pybind/autocall` secion below
PyBind.builtin.print.('hello, world!')
Import Python modules
require 'pybind'
os = PyBind.import('os')
puts os.name
# or more python-like
require 'pybind'
include PyBind::Import
pyimport 'os'
puts os.name
Customize convertor between Ruby & Python object
require 'pybind'
Fraction = PyBind.import('fractions').Fraction
class PyFraction
include PyBind::PyObjectWrapper
pybind_type Fraction
end
f = Fraction.(1, 2)
f.kind_of? PyFraction # => true
f.numerator # => 1
f.denominator # => 2
Or you can map Python object to exsisting Ruby class
require 'pybind'
class Rational
include PyBind::PyObjectWrapper
Fraction = PyBind.import('fractions').Fraction
pybind_type Fraction do |pystruct|
# pystruct is a PyObjectStruct, which is a FFI::Struct
# This block defines how Python object converts to Ruby object
# By default, it's `new(pystruct)`
# For easily access the attributes, let's convert it to PyObject
pyobj = pystruct.to_ruby_object
new(pyobj.numerator, pyobj.denominator)
end
def to_python
# This block defines how Ruby object converts back to Python object
Fraction.(self.numerator, self.denominator)
end
end
If you don't like the dot everywhere before the function call (just like me), you can just require 'pybind/autocall'
.
Note that this will heavily change the behavior of your code, but the life will be easier.
require 'pybind'
require 'pybind/autocall'
# No dot anymore, if you need the function object, you need to call
# `PyBind.builtin.get_attribute(:print)`
PyBind.builtin.print('Hello, world!')
After checking out the repo, run bin/setup
to install dependencies. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
PyBind.rb originally forked from pycall
, special thanks goes to Kenta Murata (mrkn
) for his brilliant idea.
Bug reports and pull requests are welcome on GitHub at https://github.com/bbtfr/pybind.rb This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.