STY: Improve linting error messages and formatting in _savez and re…

…lated tests
numpy · a-sajjad72 · Jun 30, 2025 · Jun 30, 2025 · Jun 30, 2025 · Jul 1, 2025
commit ab1781a2e00b298c97962d3f9a20a08490a6f313
diff --git a/numpy/lib/_npyio_impl.py b/numpy/lib/_npyio_impl.py
@@ -822,7 +822,8 @@ def _savez(file, args, kwds, compress, allow_pickle=True, pickle_kwargs=None,
             key = comp.lower()
             if key not in _str_to_const:
                 raise ValueError(
-                    f"Unknown compression method: {comp!r}. Valid options: {list(_str_to_const)}"
+                    f"Unknown compression method: {comp!r}. "
+                    f"Valid options: {list(_str_to_const)}"
                 )
             comp = _str_to_const[key]
         elif isinstance(comp, int):
@@ -836,11 +837,13 @@ def _savez(file, args, kwds, compress, allow_pickle=True, pickle_kwargs=None,
 
             if comp not in _valid_ints:
                 raise ValueError(
-                    f"Unknown compression method: {comp}. Valid options: {sorted(_valid_ints)}"
+                    f"Unknown compression method: {comp}. "
+                    f"Valid options: {sorted(_valid_ints)}"
                 )
         else:
             raise TypeError(
-                "compression must be an int (zipfile constant) or a str specifying the method"
+                "compression must be an int (zipfile constant) or a str "
+                "specifying the method"
             )
 
     # Persist the (possibly normalised) compression constant back into kwargs
@@ -862,9 +865,11 @@ def _in_range(minv: int, maxv: int) -> bool:
 
         if comp == zipfile.ZIP_DEFLATED and not _in_range(0, 9):
             raise ValueError("For DEFLATED, compresslevel must be between 0 and 9.")
-        if hasattr(zipfile, "ZIP_BZIP2") and comp == zipfile.ZIP_BZIP2 and not _in_range(1, 9):
+        if (hasattr(zipfile, "ZIP_BZIP2") and comp == zipfile.ZIP_BZIP2
+                and not _in_range(1, 9)):
             raise ValueError("For BZIP2, compresslevel must be between 1 and 9.")
-        if hasattr(zipfile, "ZIP_LZMA") and comp == zipfile.ZIP_LZMA and not _in_range(0, 9):
+        if (hasattr(zipfile, "ZIP_LZMA") and comp == zipfile.ZIP_LZMA
+                and not _in_range(0, 9)):
             raise ValueError("For LZMA, compresslevel must be between 0 and 9.")
 
         # Store the validated compresslevel back into kwargs

diff --git a/numpy/lib/tests/test_io.py b/numpy/lib/tests/test_io.py
@@ -390,7 +390,11 @@ def test_integer_compression_constants(self, compression_const):
         a = np.arange(7)
         with temppath(suffix=".npz") as tmp:
             try:
-                np.savez_compressed(tmp, a=a, zipfile_kwargs={'compression': compression_const})
+                np.savez_compressed(
+                    tmp,
+                    a=a,
+                    zipfile_kwargs={'compression': compression_const},
+                )
                 data = np.load(tmp, allow_pickle=True)
                 assert_equal(data["a"], a)
                 data.close()
@@ -413,10 +417,18 @@ def test_compresslevel_not_allowed_for_stored(self, method, const):
         with temppath(suffix=".npz") as tmp:
             # String method
             with pytest.raises(ValueError):
-                np.savez_compressed(tmp, a=a, zipfile_kwargs={'compression': method, 'compresslevel': 1})
+                np.savez_compressed(
+                    tmp,
+                    a=a,
+                    zipfile_kwargs={'compression': method, 'compresslevel': 1},
+                )
             # Integer constant
             with pytest.raises(ValueError):
-                np.savez_compressed(tmp, a=a, zipfile_kwargs={'compression': const, 'compresslevel': 1})
+                np.savez_compressed(
+                    tmp,
+                    a=a,
+                    zipfile_kwargs={'compression': const, 'compresslevel': 1},
+                )
 
     def roundtrip(self, *args, **kwargs):
         # Delegate to the RoundtripTest harness using savez_compressed
@@ -432,7 +444,12 @@ def test_basic_compression(self, method, level):
         a = np.arange(10)
         b = np.eye(3)
         with temppath(suffix=".npz") as tmp:
-            np.savez_compressed(tmp, a=a, b=b, zipfile_kwargs={'compression': method, 'compresslevel': level})
+            np.savez_compressed(
+                tmp,
+                a=a,
+                b=b,
+                zipfile_kwargs={'compression': method, 'compresslevel': level},
+            )
             data = np.load(tmp, allow_pickle=True)
             assert_equal(data["a"], a)
             assert_equal(data["b"], b)
@@ -446,7 +463,11 @@ def test_basic_compression(self, method, level):
     def test_compression_levels(self, method, level):
         a = np.arange(100)
         with temppath(suffix=".npz") as tmp:
-            np.savez_compressed(tmp, a=a, zipfile_kwargs={'compression': method, 'compresslevel': level})
+            np.savez_compressed(
+                tmp,
+                a=a,
+                zipfile_kwargs={'compression': method, 'compresslevel': level},
+            )
             data = np.load(tmp, allow_pickle=True)
             assert_equal(data["a"], a)
             data.close()
@@ -463,7 +484,11 @@ def test_mixed_data_types(self):
                                 struct=struct,
                                 obj=obj,
                                 strs=strs,
-                                zipfile_kwargs={'compression': 'bzip2', 'compresslevel': 5})
+                                zipfile_kwargs={
+                                    'compression': 'bzip2',
+                                    'compresslevel': 5,
+                                },
+                            )
             data = np.load(tmp, allow_pickle=True)
             assert data["empty"].size == 0
             assert_array_equal(data["struct"], struct)
@@ -495,7 +520,11 @@ def test_invalid_compression(self, method, level, exc):
             with pytest.raises(exc):
                 np.savez_compressed(tmp,
                                     a=a,
-                                    zipfile_kwargs={'compression': method, 'compresslevel': level})
+                                    zipfile_kwargs={
+                                        'compression': method,
+                                        'compresslevel': level,
+                                    },
+                                )
 
     def test_file_handle_and_pathlib(self):
         a = np.arange(20)
@@ -537,7 +566,11 @@ def test_mixed_positional_keyword_none_level(self):
         with temppath(suffix=".npz") as tmp:
             # positional + keyword + None opts
             np.savez_compressed(tmp, a, b=a,
-                                zipfile_kwargs={'compression': 'lzma', 'compresslevel': None})
+                                zipfile_kwargs={
+                                    'compression': 'lzma',
+                                    'compresslevel': None,
+                                },
+                            )
             data = np.load(tmp, allow_pickle=True)
             assert_array_equal(data["arr_0"], a)
             assert_array_equal(data["b"], a)