BLD, CI: Use cibuildwheel to build Emscripten/Pyodide wheels, push nightlies to Anaconda.org

.github/workflows/unit-tests.yml

@@ -347,6 +347,7 @@ jobs:
       - name: Run Tests
         uses: ./.github/actions/run-tests
 
+  # NOTE: this job must be kept in sync with the Pyodide build job in wheels.yml
   emscripten:
     # Note: the Python version, Emscripten toolchain version are determined
     # by the Pyodide version. The appropriate versions can be found in the

.github/workflows/wheels.yml

@@ -199,3 +199,58 @@ jobs:
           source ci/upload_wheels.sh
           set_upload_vars
           upload_wheels
+
+  # Build Pyodide wheels and upload them to Anaconda.org
+  # NOTE: this job is similar to the one in unit-tests.yml except for the fact
+  # that it uses cibuildwheel instead of a standard Pyodide xbuildenv setup.
+  build_pyodide_wheels:
+    name: Build wheel for cp312-pyodide_wasm32
+    # Run on schedule, manual (workflow dispatch), and push events
+    # Skip on PRs, because these are running in the unit tests job already
+
+    # TODO: Uncomment the following condition(s) when this PR is ready to be merged
+    # if: >-
+    #   (github.event_name == 'schedule') ||
+    #   (github.event_name == 'workflow_dispatch') &&
+    #   (github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v') && ( ! endsWith(github.ref, 'dev0')))
+
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout pandas Repo
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+        # Note: Pyodide 0.26.0 is supported with Python 3.12. For more information, see
+        # https://github.com/pyodide/pyodide/blob/main/Makefile.envs
+      - name: Set up Python for Pyodide
+        id: setup-python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Build WASM wheel for pandas
+        uses: pypa/cibuildwheel@v2.19.0
+        with:
+          output-dir: ./wheelhouse
+        env:
+          CIBW_PLATFORM: pyodide
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: pyodide_wheel
+          path: ./wheelhouse/*.whl
+
+      - name: Upload Pyodide wheels
+        if: >-
+          success() &&
+          (github.event_name == 'schedule') ||
+          (github.event_name == 'workflow_dispatch') &&
+          (github.repository == 'pandas-dev/pandas')
+        shell: bash -el {0}
+        env:
+          PANDAS_NIGHTLY_UPLOAD_TOKEN: ${{ secrets.PANDAS_NIGHTLY_UPLOAD_TOKEN }}
+        run: |
+          source ci/upload_wheels.sh
+          set_upload_vars
+          upload_wheels

pandas/tests/test_common.py

@@ -8,6 +8,8 @@
 import numpy as np
 import pytest
 
+from pandas.compat import WASM
+
 import pandas as pd
 from pandas import Series
 import pandas._testing as tm
@@ -234,6 +236,7 @@ def test_temp_setattr(with_exception):
     assert ser.name == "first"
 
 
+@pytest.mark.skipif(WASM, reason="Can't start subprocesses in WASM")
 @pytest.mark.single_cpu
 def test_str_size():
     # GH#21758

pyproject.toml

@@ -178,6 +178,16 @@ test-command = ""
 select = "*-macosx*"
 environment = {CFLAGS="-g0"}
 
+[[tool.cibuildwheel.overrides]]
+select = "*pyodide*"
+test-requires = "pytest>=7.3.2 hypothesis>=6.46.1"
+# Pyodide repairs wheels on its own, using auditwheel-emscripten
+repair-wheel-command = ""
+test-command = """
+  PANDAS_CI='1' python -c 'import pandas as pd; \
+  pd.test(extra_args=["-m not clipboard and not single_cpu and not slow and not network and not db", "--no-strict-data-files"]);' \
+  """
+
 [tool.ruff]
 line-length = 88
 target-version = "py310"