Mypy disallow untyped calls (#4140)

.github/workflows/test-python.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ "3.7", "3.10" ]
+        python-version: [ "3.10" ]
     steps:
       - uses: actions/checkout@v3
       - name: Install latest Rust nightly
@@ -51,3 +51,49 @@ jobs:
         run: |
           pip uninstall pandas -y
           python -c "import polars"
+
+  test-python-37:
+    name: Build and test Python 3.7
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [ "3.7" ]
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install latest Rust nightly
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly-2022-06-22
+          override: true
+          components: rustfmt, clippy
+      - name: Set up Python
+        uses: actions/setup-python@v3
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r py-polars/build.requirements.txt
+      - name: Run formatting checks
+        run: |
+          cd py-polars && black --check . && blackdoc --check . && isort --check . && rustup override set nightly-2022-06-22 && cargo fmt --all -- --check && cd ..
+      - name: Run linting
+        run: |
+          cd py-polars && flake8 && cd ..
+      # this step is different, note the flag
+      - name: Run type checking
+        run: |
+          cd py-polars && mypy --allow-untyped-calls && cd ..
+      - name: Run tests
+        run: |
+          export RUSTFLAGS="-C debuginfo=0"
+          cd py-polars && rustup override set nightly-2022-06-22 && make venv && make test-with-cov
+          cargo clippy
+      - name: Check doc examples
+        run: |
+          cd py-polars && make doctest
+      # test if we can import polars without any requirements
+      - name: Import polars
+        run: |
+          pip uninstall pandas -y
+          python -c "import polars"

py-polars/polars/internals/series.py

@@ -2296,7 +2296,7 @@ def to_numpy(
             kwargs will be sent to pyarrow.Array.to_numpy
         """
 
-        def convert_to_date(arr):  # type: ignore[no-untyped-def]
+        def convert_to_date(arr: np.ndarray) -> np.ndarray:
             if self.dtype == Date:
                 tp = "datetime64[D]"
             elif self.dtype == Duration:

py-polars/pyproject.toml

@@ -35,7 +35,7 @@ warn_unused_ignores = true
 strict_concatenate = true
 # TODO: Uncomment flags below and fix mypy errors
 # disallow_any_generics = true
-# disallow_untyped_calls = true
+disallow_untyped_calls = true
 warn_redundant_casts = true
 # warn_return_any = true
 # no_implicit_reexport = true

py-polars/tests/test_df.py

@@ -1096,13 +1096,13 @@ def test_hashing_on_python_objects() -> None:
     df = pl.DataFrame({"a": [1, 1, 3, 4], "b": [1, 1, 2, 2]})
 
     class Foo:
-        def __init__(self):  # type: ignore[no-untyped-def]
+        def __init__(self) -> None:
             pass
 
-        def __hash__(self):  # type: ignore[no-untyped-def]
+        def __hash__(self) -> int:
             return 0
 
-        def __eq__(self, other):  # type: ignore[no-untyped-def]
+        def __eq__(self, other: Any) -> bool:
             return True
 
     df = df.with_column(pl.col("a").apply(lambda x: Foo()).alias("foo"))
@@ -1304,10 +1304,10 @@ def name_generator() -> Iterator[str]:
 
 def test_extension() -> None:
     class Foo:
-        def __init__(self, value):  # type: ignore[no-untyped-def]
+        def __init__(self, value: Any) -> None:
             self.value = value
 
-        def __repr__(self):  # type: ignore[no-untyped-def]
+        def __repr__(self) -> str:
             return f"foo({self.value})"
 
     foos = [Foo(1), Foo(2), Foo(3)]