PyOpenCL OpenCL Python Bindings

I’m pleased to announce the release of PyOpenCL 0.90, a complete, functional Python wrapper around OpenCL.

Its home page is at

PyOpenCL has complete documentation and a Wiki.

Download PyOpenCL here from its page in the Python package index.

Since there are a few competing efforts, what sets PyOpenCL apart?

    Object cleanup tied to lifetime of objects. This idiom, often called RAII in C++, makes it much easier to write correct, leak- and crash-free code.

    Completeness. PyOpenCL puts the full power of OpenCL’s API at your disposal, if you wish. Every obscure get_info() query and all CL calls are accessible.

    Automatic Error Checking. All errors are automatically translated into Python exceptions.

    Speed. PyOpenCL’s base layer is written in C++, so all the niceties above are virtually free.

    Helpful, complete Documentation

    Liberal license. PyOpenCL is open-source and free for commercial, academic, and private use under the MIT/X11 license.

If that sounds similar to PyOpenCL’s sister project PyCUDA, that is by no means a coincidence.

Here’s some sample code to give you an impression:

import pyopencl as cl

import numpy

import numpy.linalg as la

a = numpy.random.rand(50000).astype(numpy.float32)

b = numpy.random.rand(50000).astype(numpy.float32)

ctx = cl.create_context_from_type(cl.device_type.ALL)

queue = cl.CommandQueue(ctx)

mf = cl.mem_flags

a_buf = cl.create_host_buffer(

		ctx, mf.READ_ONLY | mf.COPY_HOST_PTR, a)

b_buf = cl.create_host_buffer(

		ctx, mf.READ_ONLY | mf.COPY_HOST_PTR, b)

dest_buf = cl.create_buffer(ctx, mf.WRITE_ONLY, b.nbytes)

prg = cl.create_program_with_source(ctx, """

	__kernel void sum(__global const float *a,

	__global const float *b, __global float *c)


	  int gid = get_global_id(0);

	  c[gid] = a[gid] + b[gid];



prg.sum(queue, a.shape, a_buf, b_buf, dest_buf)

a_plus_b = numpy.empty_like(a)

cl.enqueue_read_buffer(queue, dest_buf, a_plus_b).wait()

print la.norm(a_plus_b - (a+b))