youknowone · Sep 28, 2026 · Sep 28, 2026 · Oct 9, 2026 · Oct 9, 2026 · Oct 9, 2026
diff --git a/.cspell.dict/python-more.txt b/.cspell.dict/python-more.txt
@@ -51,6 +51,7 @@ dllhandle
 docstring
 docstrings
 dunder
+dunders
 endianness
 endpos
 eventmask

diff --git a/.cspell.dict/rust-more.txt b/.cspell.dict/rust-more.txt
@@ -83,7 +83,9 @@ trai
 ulonglong
 unic
 unistd
+ungil
 unraw
+unsendable
 unsync
 wasip1
 wasip2

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -1217,3 +1217,97 @@
 
       - name: cargo doc
         run: cargo doc --locked
+
+  pyo3:
+    # Skip the build when rust sources did not change.
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
+    needs:
+      - determine_changes
+    env:
+      RUST_BACKTRACE: full
+      RUN_PYO3: ${{ needs.determine_changes.outputs.rust_code == 'true' || github.ref == 'refs/heads/main' }}
+    name: Run pyo3 tests (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60
+    strategy:
+      matrix:
+        os: [macos-latest, ubuntu-latest, windows-2025]
+      fail-fast: false
+    steps:
+      - name: Skip pyo3 tests when sources did not change
+        if: env.RUN_PYO3 != 'true'
+        run: echo "No rust source changes; required check is green without rebuilding."
+
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        if: env.RUN_PYO3 == 'true'
+        with:
+          persist-credentials: false
+
+      - uses: dtolnay/rust-toolchain@stable
+        if: env.RUN_PYO3 == 'true'
+
+      - name: Use a short Cargo home on Windows
+        if: env.RUN_PYO3 == 'true' && runner.os == 'Windows'
+        shell: pwsh
+        run: |
+          "CARGO_HOME=$env:RUNNER_TEMP\c" >> $env:GITHUB_ENV
+          git config --global core.longpaths true
+
+      - name: Restore cache
+        if: env.RUN_PYO3 == 'true'
+        uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            ${{ runner.temp }}/c/registry/index/
+            ${{ runner.temp }}/c/registry/cache/
+            ${{ runner.temp }}/c/git/db/
+            target/
+          key: ${{ runner.os }}-${{ hashFiles('**/Cargo.toml') }}-
+          restore-keys: |
+            ${{ runner.os }}-stable--${{ hashFiles('**/Cargo.toml') }}-
+            ${{ runner.os }}-stable--
+        # Windows runners randomly crashes, https://github.com/actions/cache/issues/1754
+        continue-on-error: true
+
+      - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        if: env.RUN_PYO3 == 'true'
+        id: python
+        with:
+          python-version: "3.14"
+
+      - name: Install macOS dependencies
+        if: env.RUN_PYO3 == 'true'
+        uses: ./.github/actions/install-macos-deps
+
+      - name: build rustpython
+        if: env.RUN_PYO3 == 'true'
+        run: cargo build --locked --release --verbose --features=threading,pyo3 ${{ env.CARGO_ARGS }}
+        env:
+          PYO3_PYTHON: ${{ steps.python.outputs.python-path }}
+
+      # Shared libpython is not on the default Linux loader path. Windows
+      # finds python3xx.dll via PATH; the macOS framework install name is absolute.
+      - name: Locate libpython
+        id: libpython
+        if: env.RUN_PYO3 == 'true' && runner.os == 'Linux'
+        shell: bash
+        env:
+          PYO3_PYTHON: ${{ steps.python.outputs.python-path }}
+        run: |
+          libdir="$("$PYO3_PYTHON" -c "import sysconfig; print(sysconfig.get_config_var('LIBDIR'))")"
+          echo "libdir=${libdir}" >> "$GITHUB_OUTPUT"
+
+      - name: Run pyo3 tests
+        if: env.RUN_PYO3 == 'true'
+        shell: bash
+        env:
+          LIBDIR: ${{ steps.libpython.outputs.libdir }}
+        run: |
+          if [ -n "$LIBDIR" ]; then
+            export LD_LIBRARY_PATH="${LIBDIR}${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
+          fi
+          target/release/rustpython crates/module_pyo3/tests/test_module_pyo3.py
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -12,7 +12,7 @@ license.workspace = true
 [features]
 capi = ["dep:rustpython-capi", "threading"]
 default = ["threading", "stdlib", "stdio", "importlib", "ssl-rustls-aws-lc", "host_env", "mimalloc", "doc", "ucd_3_2_0"]
-doc = ["rustpython-vm/doc", "rustpython-stdlib?/doc"]
+doc = ["rustpython-vm/doc", "rustpython-stdlib?/doc", "rustpython-module_pyo3?/doc"]
 mimalloc = ["dep:mimalloc"]
 host_env = ["rustpython-vm/host_env", "rustpython-stdlib?/host_env"]
 importlib = ["rustpython-vm/importlib"]
@@ -23,7 +23,11 @@ flame-it = ["rustpython-vm/flame-it", "rustpython-stdlib/flame-it", "flame", "fl
 freeze-stdlib = ["stdlib", "rustpython-vm/freeze-stdlib", "rustpython-pylib?/freeze-stdlib"]
 jit = ["rustpython-vm/jit"]
 opcode-histogram = ["rustpython-vm/opcode-histogram"]
-threading = ["rustpython-vm/threading", "rustpython-stdlib/threading"]
+threading = [
+    "rustpython-vm/threading",
+    "rustpython-stdlib/threading",
+    "rustpython-module_pyo3?/threading",
+]
 sqlite = ["rustpython-stdlib/sqlite"]
 ssl = ["host_env", "rustpython-stdlib?/ssl"]
 ssl-rustls = ["ssl", "rustpython-stdlib/ssl-rustls"]
@@ -33,6 +37,7 @@ ssl-openssl = ["ssl", "rustpython-stdlib/ssl-openssl"]
 ssl-openssl-vendor = ["ssl-openssl", "rustpython-stdlib/ssl-openssl-vendor"]
 tkinter = ["rustpython-stdlib/tkinter"]
 ucd_3_2_0 = ["rustpython-stdlib?/ucd_3_2_0"]
+pyo3 = ["dep:rustpython-module_pyo3"]
 
 [build-dependencies]
 winresource = "0.1"
@@ -42,6 +47,7 @@ rustpython-capi = { workspace = true, optional = true }
 rustpython-pylib = { workspace = true, optional = true }
 rustpython-stdlib = { workspace = true, optional = true, default-features = false, features = ["compiler"] }
 rustpython-vm = { workspace = true, features = ["compiler", "gc"] }
+rustpython-module_pyo3 = { workspace = true, optional = true }
 
 log = { workspace = true }
 flame = { workspace = true, optional = true }
@@ -200,6 +206,7 @@ rustpython-sre_engine = { path = "crates/sre_engine", version = "0.6.1" }
 rustpython-unicode = { path = "crates/unicode", default-features = false, version = "0.6.1" }
 rustpython-wtf8 = { path = "crates/wtf8", version = "0.6.1" }
 rustpython-doc = { path = "crates/doc", version = "0.6.1" }
+rustpython-module_pyo3 = { path = "crates/module_pyo3", version = "0.6.1", default-features = false }
 
 # Use the RustPython Ruff fork for RustPython public `_ast` metadata.
 ruff_python_parser = { package = "rustpython-ruff_python_parser", git = "https://github.com/RustPython/ruff.git", rev = "9290a8849542134d83f77e9360e7f0b93897fd93" }

diff --git a/crates/module_pyo3/Cargo.toml b/crates/module_pyo3/Cargo.toml
@@ -0,0 +1,25 @@
+[package]
+name = "rustpython-module_pyo3"
+description = "RustPython pyo3 module - bridge to CPython via PyO3"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+repository.workspace = true
+license.workspace = true
+
+[features]
+default = ["doc"]
+doc = ["rustpython-vm/doc"]
+threading = ["rustpython-vm/threading"]
+
+[dependencies]
+rustpython-vm = { workspace = true }
+rustpython-derive = { workspace = true }
+pyo3 = { workspace = true, features = ["auto-initialize"] }
+malachite-bigint = { workspace = true }
+num-complex = { workspace = true }
+num-traits = { workspace = true }
+
+[lints]
+workspace = true
-Original file line number
+Diff line change
@@ Expand Up / @@ -83,7 +83,9 @@ trai @@
     ulonglong
     unic
     unistd
+    ungil
     unraw
+    unsendable
     unsync
     wasip1
     wasip2
@@ Expand Down @@