JuliaPy · cjdoris · Oct 9, 2025 · Oct 9, 2025 · Oct 9, 2025 · Oct 10, 2025
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
@@ -19,7 +19,7 @@ jobs:
       matrix:
         arch: [x64] # x86 unsupported by MicroMamba
         os: [ubuntu-latest, windows-latest, macos-latest]
-        jlversion: ['1','1.9']
+        jlversion: ['1','1.10']
         pythonexe: ['@CondaPkg']
         include:
         - arch: x64
@@ -66,7 +66,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        pyversion: ["3", "3.9"]
+        pyversion: ["3", "3.10"]
         juliaexe: ["@JuliaPkg"]
         include:
         - os: ubuntu-latest
@@ -84,17 +84,25 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.pyversion }}
+
+      - name: Check Python OpenSSL version (see setup_julia)
+        shell: python
+        run: |
+          import ssl
+          assert ssl.OPENSSL_VERSION_INFO < (3, 5)
 
       - name: Set up uv
-        uses: astral-sh/setup-uv@v6
+        uses: astral-sh/setup-uv@v7
         with:
           python-version: ${{ matrix.pyversion }}
 
       - name: Set up Julia
         id: setup_julia
         uses: julia-actions/setup-julia@v2
         with:
-          version: '1'
+          # Python in the GitHub runners ships with OpenSSL 3.0. Julia 1.12 requires
+          # OpenSSL 3.5. Therefore juliapkg requires Julia 1.11 or lower.
+          version: '1.11'
 
       - name: Set up test Julia project
         if: ${{ matrix.juliaexe == 'julia' }}

diff --git a/CondaPkg.toml b/CondaPkg.toml
@@ -1,12 +1,17 @@
-[deps.libstdcxx]
+
+[deps.openssl]
 version = "<=julia"
 
-[deps.libstdcxx-ng]
+[deps.libstdcxx]
 version = "<=julia"
 
-[deps.openssl]
+[deps.libstdcxx-ng]
 version = "<=julia"
 
 [deps.python]
 build = "**cpython**"
-version = ">=3.9,<4"
+version = ">=3.10,<4"
+
+[dev.deps]
+matplotlib = ""
+pyside6 = ""
diff --git a/Project.toml b/Project.toml
@@ -17,7 +17,7 @@ UnsafePointers = "e17b2a0c-0bdf-430a-bd0c-3a23cae4ff39"
 [compat]
 Aqua = "0 - 999"
 CategoricalArrays = "0.10, 1"
-CondaPkg = "0.2.30"
+CondaPkg = "0.2.33"
 Dates = "1"
 Libdl = "1"
 MacroTools = "0.5"
@@ -29,7 +29,7 @@ Tables = "1"
 Test = "1"
 TestItemRunner = "0 - 999"
 UnsafePointers = "1"
-julia = "1.9"
+julia = "1.10"
 
 [extensions]
 PyCallExt = "PyCall"

diff --git a/README.md b/README.md
@@ -14,7 +14,7 @@ Bringing [**Python®**](https://www.python.org/) and [**Julia**](https://juliala
 - Fast non-copying conversion of numeric arrays in either direction: modify Python arrays (e.g. `bytes`, `array.array`, `numpy.ndarray`) from Julia or Julia arrays from Python.
 - Helpful wrappers: interpret Python sequences, dictionaries, arrays, dataframes and IO streams as their Julia counterparts, and vice versa.
 - Beautiful stack-traces.
-- Supports modern systems: tested on Windows, MacOS and Linux, 64-bit, Julia 1.9 upwards and Python 3.9 upwards.
+- Supports modern systems: tested on Windows, MacOS and Linux, 64-bit, Julia 1.10 upwards and Python 3.10 upwards.
 
 ⭐ If you like this, a GitHub star would be lovely thank you. ⭐
 

diff --git a/docs/src/faq.md b/docs/src/faq.md
@@ -108,3 +108,11 @@ using PythonCall
 
 np = pyimport("numpy")
 ```
+
+## What versions of Python and Julia do you support?
+
+Each release of PythonCall and JuliaCall will support and require:
+- Any currently supported version of Python, [see here](https://devguide.python.org/versions/). Currently 3.10+.
+- The current Julia LTS version and newer, [see here](https://julialang.org/downloads/#long_term_support_release). Currently 1.10+.
+
+Only the latest patch release within each minor version is supported.
diff --git a/docs/src/index.md b/docs/src/index.md
@@ -7,4 +7,4 @@ Bringing [**Python®**](https://www.python.org/) and [**Julia**](https://juliala
 - Fast non-copying conversion of numeric arrays in either direction: modify Python arrays (e.g. `bytes`, `array.array`, `numpy.ndarray`) from Julia or Julia arrays from Python.
 - Helpful wrappers: interpret Python sequences, dictionaries, arrays, dataframes and IO streams as their Julia counterparts, and vice versa.
 - Beautiful stack-traces.
-- Works anywhere: tested on Windows, MacOS and Linux, 32- and 64-bit, Julia Julia 1.9 upwards and Python 3.9 upwards.
+- Works anywhere: tested on Windows, MacOS and Linux, 32- and 64-bit, Julia Julia 1.10 upwards and Python 3.10 upwards.
diff --git a/docs/src/juliacall-reference.md b/docs/src/juliacall-reference.md
@@ -158,13 +158,13 @@ This wraps any Julia `AbstractVector` value. It is a subclass of `juliacall.Arra
 
 `````@customdoc
 juliacall.DictValue - Class
-This wraps any Julia `AbstractDict` value. It is a subclass of `collections.abc.Mapping` and
+This wraps any Julia `AbstractDict` value. It is a subclass of `collections.abc.MutableMapping` and
 behaves similar to a Python `dict`.
 `````
 
 `````@customdoc
 juliacall.SetValue - Class
-This wraps any Julia `AbstractSet` value. It is a subclass of `collections.abc.Set` and
+This wraps any Julia `AbstractSet` value. It is a subclass of `collections.abc.MutableSet` and
 behaves similar to a Python `set`.
 `````
 

diff --git a/docs/src/juliacall.md b/docs/src/juliacall.md
@@ -7,6 +7,11 @@ It's as simple as
 pip install juliacall
 ```
 
+If you prefer Conda, there is a community effort to also release this on conda-forge:
+```bash
+conda install conda-forge::pyjuliapkg
+```
+
 Developers may wish to clone the repo (https://github.com/JuliaPy/PythonCall.jl) directly
 and pip install the module in editable mode. You should add `"dev":true, "path":"../.."` to
 `pysrc/juliacall/juliapkg.json` to ensure you use the development version of PythonCall
@@ -140,6 +145,10 @@ be configured in two ways:
 
 ## [Multi-threading](@id py-multi-threading)
 
+!!! warning
+
+    Multi-threading support is experimental and can change without notice.
+
 From v0.9.22, JuliaCall supports multi-threading in Julia and/or Python, with some
 caveats.
 

diff --git a/docs/src/pythoncall.md b/docs/src/pythoncall.md
@@ -8,7 +8,7 @@ This package is in the general registry, so to install just type `]` in the Juli
 pkg> add PythonCall
 ```
 
-## Getting started
+## [Getting started](@id py_getting_started)
 
 Import the module with:
 
@@ -91,6 +91,52 @@ Python: ValueError('some error')
 With the functions introduced so far, you have access to the vast majority of Python's
 functionality.
 
+## Executing Python scripts
+
+A common use case is calling multiple blocks of Python code from Julia interactively. This can be accomplished in PythonCall via the [@pyexec](@ref) macro. For example, the sentence parsing application in the [Getting started](@ref py_getting_started) section could be rewritten as:
+
+```julia-repl
+julia> @pyexec """
+           global re
+           import re
+
+           def my_sentence(s):
+               words = re.findall("[a-zA-Z]+", s)
+               sentence = " ".join(words)
+               return sentence
+           """ => my_sentence
+Python: <function my_sentence at 0x7d83bb1b01a0>
+
+julia> sentence = my_sentence("PythonCall.jl is very useful!")
+Python: 'PythonCall jl is very useful'
+```
+
+Note the use of the `global` keyword to make the `re` package accessible in global scope, and the `=> my_sentence` syntax to create a Julia function named `my_sentence` that calls to the Python function of the same name. This syntax also supports calling to multiple functions and passing data back-and-forth:
+
+```julia-repl
+julia> @pyexec (num=10) => """
+           def add(a, b):
+             return a + b
+
+           def subtract(a, b):
+               return a - b
+
+           plusone = num + 1
+           """ => (add, subtract, plusone::Float64)
+(add = <py function add at 0x721b001a7cc0>, subtract = <py function subtract at 0x721b001a7d70>, plusone = 11.0)
+
+julia> add(4, 3)
+Python: 7
+
+julia> subtract(4, 3)
+Python: 1
+
+julia> plusone
+11.0
+```
+
+Here we demonstrate passing a named variable, `num`, via the use of the `=>` syntax again, and returning named output, with the last element, `plusone`, being cast to a Julia object via the `::` syntax. See [@pyexec](@ref), [@pyeval](@ref), and their functional forms [pyexec](@ref) and [pyeval](@ref), for more.
+
 ## Conversion between Julia and Python
 
 A Julia object can be converted to a Python one either explicitly (such as `Py(x)`) or
@@ -369,6 +415,10 @@ See [Installing Python packages](@ref python-deps).
 
 ## [Multi-threading](@id jl-multi-threading)
 
+!!! warning
+
+    Multi-threading support is experimental and can change without notice.
+
 From v0.9.22, PythonCall supports multi-threading in Julia and/or Python, with some
 caveats.
 

diff --git a/docs/src/releasenotes.md b/docs/src/releasenotes.md
@@ -1,5 +1,13 @@
 # Release Notes
 
+## Unreleased
+* Minimum supported Python version is now 3.10.
+* Minimum supported Julia version is now 1.10.
+* Showing `Py` now respects the `compact` option - output is limited to a single line of
+  at most the display width.
+* Support policy now documented in the FAQ.
+* Bug fixes.
+
 ## 0.9.28 (2025-09-17)
 * Added `NumpyDates`: NumPy-compatible DateTime64/TimeDelta64 types and units.
 * Added `pyconvert` rules for NumpyDates types.

diff --git a/pyproject.toml b/pyproject.toml
@@ -12,8 +12,8 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.9, <4"
-dependencies = ["juliapkg >=0.1.17, <0.2"]
+requires-python = ">=3.10, <4"
+dependencies = ["juliapkg >=0.1.21, <0.2"]
 
 [dependency-groups]
 dev = [

diff --git a/pysrc/juliacall/juliapkg-dev.json b/pysrc/juliacall/juliapkg-dev.json
@@ -1,5 +1,5 @@
 {
-    "julia": "~1.9, ^1.10.3",
+    "julia": "^1.10.3",
     "packages": {
         "PythonCall": {
             "uuid": "6099a3de-0909-46bc-b1f4-468b9a2dfc0d",

diff --git a/pysrc/juliacall/juliapkg.json b/pysrc/juliacall/juliapkg.json
@@ -1,5 +1,5 @@
 {
-    "julia": "~1.9, ^1.10.3",
+    "julia": "^1.10.3",
     "packages": {
         "PythonCall": {
             "uuid": "6099a3de-0909-46bc-b1f4-468b9a2dfc0d",

diff --git a/src/C/context.jl b/src/C/context.jl
@@ -29,6 +29,79 @@ function _atpyexit()
     return
 end
 
+
+function setup_onfixedthread()
+    channel_input = Channel(1)
+    channel_output = Channel(1)
+    islaunched = Ref(false) # use Ref to avoid closure boxing of variable
+    function launch_worker(tid)
+        islaunched[] && error("Cannot launch more than once: call setup_onfixedthread again if need be.")
+        islaunched[] = true
+        worker_task = Task() do
+            while true
+                f = take!(channel_input)
+                ret = try
+                    Some(invokelatest(f))
+                    # invokelatest is necessary for development and interactive use.
+                    # Otherwise, only a method f defined in a world prior to the call of
+                    # launch_worker would work.
+                catch e
+                    e, catch_backtrace()
+                end
+                put!(channel_output, ret)
+            end
+        end
+        # code adapted from set_task_tid! in StableTasks.jl, itself taken from Dagger.jl
+        worker_task.sticky = true
+        for _ in 1:100
+            # try to fix the task id to tid, retrying up to 100 times
+            ret = ccall(:jl_set_task_tid, Cint, (Any, Cint), worker_task, tid-1)
+            if ret == 1
+                break # success
+            elseif ret == 0
+                yield()
+            else
+                error("Unexpected retcode from jl_set_task_tid: $ret")
+            end
+        end
+        if Threads.threadid(worker_task) != tid
+            error("Failed setting the thread ID to $tid.")
+        end
+        schedule(worker_task)
+    end
+    function onfixedthread(f)
+        put!(channel_input, f)
+        ret = take!(channel_output)
+        if ret isa Tuple
+            e, backtrace = ret
+            printstyled(stderr, "ERROR: "; color=:red, bold=true)
+            showerror(stderr, e)
+            Base.show_backtrace(stderr, backtrace)
+            println(stderr)
+            throw(e) # the stacktrace of the actual error is printed above
+        else
+            something(ret)
+        end
+    end
+    launch_worker, onfixedthread
+end
+
+# launch_on_main_thread is used in init_context(), after which on_main_thread becomes usable
+const launch_on_main_thread, on_main_thread = setup_onfixedthread()
+
+"""
+    on_main_thread(f)
+
+Execute `f()` on the main thread.
+
+!!! warning
+    The value returned by `on_main_thread(f)` cannot be type-inferred by the compiler:
+    if necessary, use explicit type annotations such as `on_main_thread(f)::T`, where `T` is
+    the expected return type.
+"""
+on_main_thread
+
+
 function init_context()
 
     CTX.is_embedded = hasproperty(Base.Main, :__PythonCall_libptr)
@@ -236,10 +309,12 @@ function init_context()
         error("Cannot parse version from version string: $(repr(verstr))")
     end
     CTX.version = VersionNumber(vermatch.match)
-    v"3.9" ≤ CTX.version < v"4" || error(
-        "Only Python 3.9+ is supported, this is Python $(CTX.version) at $(CTX.exe_path===missing ? "unknown location" : CTX.exe_path).",
+    v"3.10" ≤ CTX.version < v"4" || error(
+        "Only Python 3.10+ is supported, this is Python $(CTX.version) at $(CTX.exe_path===missing ? "unknown location" : CTX.exe_path).",
     )
 
+    launch_on_main_thread(Threads.threadid()) # makes on_main_thread usable
+
     @debug "Initialized PythonCall.jl" CTX.is_embedded CTX.is_initialized CTX.exe_path CTX.lib_path CTX.lib_ptr CTX.pyprogname CTX.pyhome CTX.version
 
     return

diff --git a/src/Compat/gui.jl b/src/Compat/gui.jl
@@ -159,7 +159,7 @@ function init_gui()
 
         # add a hook to automatically call fix_qt_plugin_path()
         fixqthook =
-            Py(() -> (Core.CONFIG.auto_fix_qt_plugin_path && fix_qt_plugin_path(); nothing))
+            Py(() -> (PythonCall.CONFIG.auto_fix_qt_plugin_path && fix_qt_plugin_path(); nothing))
         pymodulehooks.add_hook("PyQt4", fixqthook)
         pymodulehooks.add_hook("PyQt5", fixqthook)
         pymodulehooks.add_hook("PySide", fixqthook)