julia_import

Import the Julia environment.

This provides additional functionality on top of juliapkg (which automatically downloads Julia packages for us). It will import the juliacall module to create a Julia environment (as jl ), and uses it to import the DataAxesFormats.jl Julia package.

You can control the behavior using the following environment variables:

  • PYTHON_JULIACALL_HANDLE_SIGNALS (by default, yes ). This is needed to avoid segfaults when calling Julia from Python.

  • PYTHON_JULIACALL_THREADS (by default, auto ). By default Julia will use all the threads available in the machine. On machines with hyper-threading you may want to specify only half the number of threads (that is, just have one thread per physical core) as that should provide better performance for compute-intensive (as opposed to IO-intensive) code.

  • PYTHON_JULIACALL_OPTLEVEL (by default, 3 ).

This code is based on the code from the pysr Python package, adapted to our needs. TODO: Much of this is replicated in all our Python packages that invoke Julia.

dafpy.julia_import. jl = Julia: Main

The interface to the Julia run-time.

dafpy.julia_import. jl_version = (1, 11, 5)

The version of Julia being used.

class dafpy.julia_import. UndefInitializer [source]

A Python class to use instead of Julia’s UndefInitializer . We need this to allow @overload to work in the presence of Undef .

dafpy.julia_import. Undef = <dafpy.julia_import.UndefInitializer object>

A Python value to use instead of Julia’s undef . We need this to allow @overload to work in the presence of undef .

dafpy.julia_import. use_default_julia_environment ( ) → None [source]

Force JuliaCall to use your default environment (whatever that is). By default JuliaCall creates its own separate independent environment, which means that it re-downloads and re-installs all the dependency packages there. This is nice if you don’t otherwise use Julia and/or don’t care about the wasted disk space and initial installation time and manual control over package versions. It sucks if you do otherwise use Julia, and/or you want manual control over the version of some of the packages (e.g., if you are actively developing them). You would think there would a built-in method for doing this in JuliaCall, right?

To make this easier (and trigger it before actually importing packages), you can set the PYTHON_JULIACALL_USE_DEFAULT_ENVIRONMENT environment variable to yes , and then import dafpy will call use_default_julia_environment for you. Sigh.