Add Python integration

Author: jpsamaroo

Diff for: Project.toml

@@ -32,13 +32,15 @@ Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 GraphViz = "f526b714-d49f-11e8-06ff-31ed36ee7ee0"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
+PythonCall = "6099a3de-0909-46bc-b1f4-468b9a2dfc0d"
 
 [extensions]
 DistributionsExt = "Distributions"
 GraphVizExt = "GraphViz"
 GraphVizSimpleExt = "Colors"
 JSON3Ext = "JSON3"
 PlotsExt = ["DataFrames", "Plots"]
+PythonExt = "PythonCall"
 
 [compat]
 Adapt = "4.0.4"
@@ -69,3 +71,4 @@ Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 GraphViz = "f526b714-d49f-11e8-06ff-31ed36ee7ee0"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
+PythonCall = "6099a3de-0909-46bc-b1f4-468b9a2dfc0d"

Diff for: ext/PythonExt.jl

@@ -0,0 +1,47 @@
+module PythonExt
+
+if isdefined(Base, :get_extension)
+    using PythonCall
+else
+    using ..PythonCall
+end
+
+import Dagger
+import Dagger: Processor, OSProc, ThreadProc, Chunk
+import Distributed: myid
+
+const CPUProc = Union{OSProc, ThreadProc}
+
+struct PythonProcessor <: Processor
+    owner::Int
+end
+
+Dagger.root_worker_id(proc::PythonProcessor) = proc.owner
+Dagger.get_parent(proc::PythonProcessor) = OSProc(proc.owner)
+Dagger.default_enabled(::PythonProcessor) = true
+
+Dagger.iscompatible_func(::ThreadProc, opts, ::Type{Py}) = false
+Dagger.iscompatible_func(::PythonProcessor, opts, ::Type{Py}) = true
+Dagger.iscompatible_arg(::PythonProcessor, opts, ::Type{Py}) = true
+Dagger.iscompatible_arg(::PythonProcessor, opts, ::Type{<:PyArray}) = true
+
+Dagger.move(from_proc::CPUProc, to_proc::PythonProcessor, x::Chunk) =
+    Dagger.move(from_proc, to_proc, Dagger.move(from_proc, Dagger.get_parent(to_proc), x))
+Dagger.move(::CPUProc, ::PythonProcessor, x) = Py(x)
+Dagger.move(::CPUProc, ::PythonProcessor, x::Py) = x
+Dagger.move(::CPUProc, ::PythonProcessor, x::PyArray) = x
+# FIXME: Conversion from Python to Julia
+
+function Dagger.execute!(::PythonProcessor, f, args...; kwargs...)
+    @assert f isa Py "Function must be a Python object"
+    @show f args kwargs
+    return f(args...; kwargs...)
+end
+
+function __init__()
+    Dagger.add_processor_callback!(:pythonproc) do
+        return PythonProcessor(myid())
+    end
+end
+
+end # module PythonExt