add some -> to pandas core

Author: MarcoGorelli

pandas/_config/config.py

@@ -435,13 +435,13 @@ def __init__(self, *args) -> None:
 
         self.ops = list(zip(args[::2], args[1::2]))
 
-    def __enter__(self):
+    def __enter__(self) -> None:
         self.undo = [(pat, _get_option(pat, silent=True)) for pat, val in self.ops]
 
         for pat, val in self.ops:
             _set_option(pat, val, silent=True)
 
-    def __exit__(self, *args):
+    def __exit__(self, *args) -> None:
         if self.undo:
             for pat, val in self.undo:
                 _set_option(pat, val, silent=True)

pandas/_testing/__init__.py

@@ -238,15 +238,15 @@
 _testing_mode_warnings = (DeprecationWarning, ResourceWarning)
 
 
-def set_testing_mode():
+def set_testing_mode() -> None:
     # set the testing mode filters
     testing_mode = os.environ.get("PANDAS_TESTING_MODE", "None")
     if "deprecate" in testing_mode:
         for category in _testing_mode_warnings:
             warnings.simplefilter("always", category)
 
 
-def reset_testing_mode():
+def reset_testing_mode() -> None:
     # reset the testing mode filters
     testing_mode = os.environ.get("PANDAS_TESTING_MODE", "None")
     if "deprecate" in testing_mode:
@@ -257,7 +257,7 @@ def reset_testing_mode():
 set_testing_mode()
 
 
-def reset_display_options():
+def reset_display_options() -> None:
     """
     Reset the display options for printing and representing objects.
     """

pandas/_testing/_io.py

@@ -368,7 +368,7 @@ def round_trip_localpath(writer, reader, path: str | None = None):
     return obj
 
 
-def write_to_compressed(compression, path, data, dest="test"):
+def write_to_compressed(compression, path, data, dest="test") -> None:
     """
     Write data to a compressed file.
 
@@ -424,7 +424,7 @@ def write_to_compressed(compression, path, data, dest="test"):
 # Plotting
 
 
-def close(fignum=None):
+def close(fignum=None) -> None:
     from matplotlib.pyplot import (
         close as _close,
         get_fignums,

pandas/_testing/asserters.py

@@ -68,7 +68,7 @@ def assert_almost_equal(
     rtol: float = 1.0e-5,
     atol: float = 1.0e-8,
     **kwargs,
-):
+) -> None:
     """
     Check that the left and right objects are approximately equal.
 
@@ -211,7 +211,7 @@ def _get_tol_from_less_precise(check_less_precise: bool | int) -> float:
         return 0.5 * 10**-check_less_precise
 
 
-def _check_isinstance(left, right, cls):
+def _check_isinstance(left, right, cls) -> None:
     """
     Helper method for our assert_* methods that ensures that
     the two objects being compared have the right type before
@@ -239,7 +239,7 @@ def _check_isinstance(left, right, cls):
         )
 
 
-def assert_dict_equal(left, right, compare_keys: bool = True):
+def assert_dict_equal(left, right, compare_keys: bool = True) -> None:
 
     _check_isinstance(left, right, dict)
     _testing.assert_dict_equal(left, right, compare_keys=compare_keys)
@@ -497,7 +497,7 @@ def assert_attr_equal(attr: str, left, right, obj: str = "Attributes"):
         raise_assert_detail(obj, msg, left_attr, right_attr)
 
 
-def assert_is_valid_plot_return_object(objs):
+def assert_is_valid_plot_return_object(objs) -> None:
     import matplotlib.pyplot as plt
 
     if isinstance(objs, (Series, np.ndarray)):
@@ -516,7 +516,7 @@ def assert_is_valid_plot_return_object(objs):
         assert isinstance(objs, (plt.Artist, tuple, dict)), msg
 
 
-def assert_is_sorted(seq):
+def assert_is_sorted(seq) -> None:
     """Assert that the sequence is sorted."""
     if isinstance(seq, (Index, Series)):
         seq = seq.values
@@ -526,7 +526,7 @@ def assert_is_sorted(seq):
 
 def assert_categorical_equal(
     left, right, check_dtype=True, check_category_order=True, obj="Categorical"
-):
+) -> None:
     """
     Test that Categoricals are equivalent.
 
@@ -581,7 +581,9 @@ def assert_categorical_equal(
     assert_attr_equal("ordered", left, right, obj=obj)
 
 
-def assert_interval_array_equal(left, right, exact="equiv", obj="IntervalArray"):
+def assert_interval_array_equal(
+    left, right, exact="equiv", obj="IntervalArray"
+) -> None:
     """
     Test that two IntervalArrays are equivalent.
 
@@ -610,14 +612,16 @@ def assert_interval_array_equal(left, right, exact="equiv", obj="IntervalArray")
     assert_attr_equal("inclusive", left, right, obj=obj)
 
 
-def assert_period_array_equal(left, right, obj="PeriodArray"):
+def assert_period_array_equal(left, right, obj="PeriodArray") -> None:
     _check_isinstance(left, right, PeriodArray)
 
     assert_numpy_array_equal(left._data, right._data, obj=f"{obj}._data")
     assert_attr_equal("freq", left, right, obj=obj)
 
 
-def assert_datetime_array_equal(left, right, obj="DatetimeArray", check_freq=True):
+def assert_datetime_array_equal(
+    left, right, obj="DatetimeArray", check_freq=True
+) -> None:
     __tracebackhide__ = True
     _check_isinstance(left, right, DatetimeArray)
 
@@ -627,15 +631,19 @@ def assert_datetime_array_equal(left, right, obj="DatetimeArray", check_freq=Tru
     assert_attr_equal("tz", left, right, obj=obj)
 
 
-def assert_timedelta_array_equal(left, right, obj="TimedeltaArray", check_freq=True):
+def assert_timedelta_array_equal(
+    left, right, obj="TimedeltaArray", check_freq=True
+) -> None:
     __tracebackhide__ = True
     _check_isinstance(left, right, TimedeltaArray)
     assert_numpy_array_equal(left._data, right._data, obj=f"{obj}._data")
     if check_freq:
         assert_attr_equal("freq", left, right, obj=obj)
 
 
-def raise_assert_detail(obj, message, left, right, diff=None, index_values=None):
+def raise_assert_detail(
+    obj, message, left, right, diff=None, index_values=None
+) -> None:
     __tracebackhide__ = True
 
     msg = f"""{obj} are different
@@ -725,7 +733,7 @@ def _get_base(obj):
         if left_base is right_base:
             raise AssertionError(f"{repr(left_base)} is {repr(right_base)}")
 
-    def _raise(left, right, err_msg):
+    def _raise(left, right, err_msg) -> None:
         if err_msg is None:
             if left.shape != right.shape:
                 raise_assert_detail(
@@ -762,7 +770,7 @@ def assert_extension_array_equal(
     check_exact=False,
     rtol: float = 1.0e-5,
     atol: float = 1.0e-8,
-):
+) -> None:
     """
     Check that left and right ExtensionArrays are equal.
 
@@ -878,7 +886,7 @@ def assert_series_equal(
     *,
     check_index=True,
     check_like=False,
-):
+) -> None:
     """
     Check that left and right Series are equal.
 
@@ -1145,7 +1153,7 @@ def assert_frame_equal(
     rtol=1.0e-5,
     atol=1.0e-8,
     obj="DataFrame",
-):
+) -> None:
     """
     Check that left and right DataFrame are equal.
 
@@ -1352,7 +1360,7 @@ def assert_frame_equal(
             )
 
 
-def assert_equal(left, right, **kwargs):
+def assert_equal(left, right, **kwargs) -> None:
     """
     Wrapper for tm.assert_*_equal to dispatch to the appropriate test function.
 
@@ -1393,7 +1401,7 @@ def assert_equal(left, right, **kwargs):
         assert_almost_equal(left, right)
 
 
-def assert_sp_array_equal(left, right):
+def assert_sp_array_equal(left, right) -> None:
     """
     Check that the left and right SparseArray are equal.
 
@@ -1426,12 +1434,12 @@ def assert_sp_array_equal(left, right):
     assert_numpy_array_equal(left.to_dense(), right.to_dense())
 
 
-def assert_contains_all(iterable, dic):
+def assert_contains_all(iterable, dic) -> None:
     for k in iterable:
         assert k in dic, f"Did not contain item: {repr(k)}"
 
 
-def assert_copy(iter1, iter2, **eql_kwargs):
+def assert_copy(iter1, iter2, **eql_kwargs) -> None:
     """
     iter1, iter2: iterables that produce elements
     comparable with assert_almost_equal
@@ -1463,7 +1471,7 @@ def is_extension_array_dtype_and_needs_i8_conversion(left_dtype, right_dtype) ->
     return is_extension_array_dtype(left_dtype) and needs_i8_conversion(right_dtype)
 
 
-def assert_indexing_slices_equivalent(ser: Series, l_slc: slice, i_slc: slice):
+def assert_indexing_slices_equivalent(ser: Series, l_slc: slice, i_slc: slice) -> None:
     """
     Check that ser.iloc[i_slc] matches ser.loc[l_slc] and, if applicable,
     ser[l_slc].
@@ -1477,7 +1485,7 @@ def assert_indexing_slices_equivalent(ser: Series, l_slc: slice, i_slc: slice):
         assert_series_equal(ser[l_slc], expected)
 
 
-def assert_metadata_equivalent(left, right):
+def assert_metadata_equivalent(left, right) -> None:
     """
     Check that ._metadata attributes are equivalent.
     """

pandas/_testing/contexts.py

@@ -64,7 +64,7 @@ def set_timezone(tz: str):
     import os
     import time
 
-    def setTZ(tz):
+    def setTZ(tz) -> None:
         if tz is None:
             try:
                 del os.environ["TZ"]
@@ -231,11 +231,11 @@ class RNGContext:
     def __init__(self, seed) -> None:
         self.seed = seed
 
-    def __enter__(self):
+    def __enter__(self) -> None:
 
         self.start_state = np.random.get_state()
         np.random.seed(self.seed)
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(self, exc_type, exc_value, traceback) -> None:
 
         np.random.set_state(self.start_state)

pandas/compat/pickle_compat.py

@@ -30,7 +30,7 @@
     )
 
 
-def load_reduce(self):
+def load_reduce(self) -> None:
     stack = self.stack
     args = stack.pop()
     func = stack[-1]
@@ -207,7 +207,7 @@ def find_class(self, module, name):
 Unpickler.dispatch[pkl.REDUCE[0]] = load_reduce
 
 
-def load_newobj(self):
+def load_newobj(self) -> None:
     args = self.stack.pop()
     cls = self.stack[-1]
 
@@ -231,7 +231,7 @@ def load_newobj(self):
 Unpickler.dispatch[pkl.NEWOBJ[0]] = load_newobj
 
 
-def load_newobj_ex(self):
+def load_newobj_ex(self) -> None:
     kwargs = self.stack.pop()
     args = self.stack.pop()
     cls = self.stack.pop()

pandas/conftest.py

@@ -90,7 +90,7 @@
 # pytest
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser) -> None:
     parser.addoption("--skip-slow", action="store_true", help="skip slow tests")
     parser.addoption("--skip-network", action="store_true", help="skip network tests")
     parser.addoption("--skip-db", action="store_true", help="skip db tests")
@@ -123,7 +123,7 @@ def ignore_doctest_warning(item: pytest.Item, path: str, message: str) -> None:
         item.add_marker(pytest.mark.filterwarnings(f"ignore:{message}"))
 
 
-def pytest_collection_modifyitems(items, config):
+def pytest_collection_modifyitems(items, config) -> None:
     skip_slow = config.getoption("--skip-slow")
     only_slow = config.getoption("--only-slow")
     skip_network = config.getoption("--skip-network")
@@ -231,7 +231,7 @@ def pytest_collection_modifyitems(items, config):
 
 
 @pytest.fixture
-def add_doctest_imports(doctest_namespace):
+def add_doctest_imports(doctest_namespace) -> None:
     """
     Make `np` and `pd` names available for doctests.
     """
@@ -243,7 +243,7 @@ def add_doctest_imports(doctest_namespace):
 # Autouse fixtures
 # ----------------------------------------------------------------
 @pytest.fixture(autouse=True)
-def configure_tests():
+def configure_tests() -> None:
     """
     Configure settings for all tests and test modules.
     """

pandas/core/array_algos/replace.py

@@ -67,7 +67,7 @@ def compare_or_regex_search(
 
     def _check_comparison_types(
         result: ArrayLike | bool, a: ArrayLike, b: Scalar | Pattern
-    ):
+    ) -> None:
         """
         Raises an error if the two arrays (a,b) cannot be compared.
         Otherwise, returns the comparison result as expected.

pandas/core/array_algos/take.py

@@ -337,7 +337,7 @@ def _get_take_nd_function(
 
     if func is None:
 
-        def func(arr, indexer, out, fill_value=np.nan):
+        def func(arr, indexer, out, fill_value=np.nan) -> None:
             indexer = ensure_platform_int(indexer)
             _take_nd_object(
                 arr, indexer, out, axis=axis, fill_value=fill_value, mask_info=mask_info
@@ -349,7 +349,7 @@ def func(arr, indexer, out, fill_value=np.nan):
 def _view_wrapper(f, arr_dtype=None, out_dtype=None, fill_wrap=None):
     def wrapper(
         arr: np.ndarray, indexer: np.ndarray, out: np.ndarray, fill_value=np.nan
-    ):
+    ) -> None:
         if arr_dtype is not None:
             arr = arr.view(arr_dtype)
         if out_dtype is not None:
@@ -364,7 +364,7 @@ def wrapper(
 def _convert_wrapper(f, conv_dtype):
     def wrapper(
         arr: np.ndarray, indexer: np.ndarray, out: np.ndarray, fill_value=np.nan
-    ):
+    ) -> None:
         if conv_dtype == object:
             # GH#39755 avoid casting dt64/td64 to integers
             arr = ensure_wrapped_if_datetimelike(arr)
@@ -506,7 +506,7 @@ def _take_nd_object(
     axis: int,
     fill_value,
     mask_info,
-):
+) -> None:
     if mask_info is not None:
         mask, needs_masking = mask_info
     else:

pandas/core/arrays/_mixins.py

@@ -259,7 +259,7 @@ def _validate_shift_value(self, fill_value):
         #  we can remove this and use validate_fill_value directly
         return self._validate_scalar(fill_value)
 
-    def __setitem__(self, key, value):
+    def __setitem__(self, key, value) -> None:
         key = check_array_indexer(self, key)
         value = self._validate_setitem_value(value)
         self._ndarray[key] = value