Merge remote-tracking branch 'origin/123-check-that-methods-of-table-…

…can-handle-an-empty-table' into 123-check-that-methods-of-table-can-handle-an-empty-table

docs/CHANGELOG.md

@@ -1,3 +1,15 @@
+## [0.13.0](https://github.com/Safe-DS/Stdlib/compare/v0.12.0...v0.13.0) (2023-06-01)
+
+
+### Features
+
+* add `Choice` class for possible values of hyperparameter ([#325](https://github.com/Safe-DS/Stdlib/issues/325)) ([d511c3e](https://github.com/Safe-DS/Stdlib/commit/d511c3eed779e64fc53499e7c2eb2e8292955645)), closes [#264](https://github.com/Safe-DS/Stdlib/issues/264)
+* Add `RangeScaler` transformer ([#310](https://github.com/Safe-DS/Stdlib/issues/310)) ([f687840](https://github.com/Safe-DS/Stdlib/commit/f68784057afe20d5450e9eb875fce1a07fb5fa77)), closes [#141](https://github.com/Safe-DS/Stdlib/issues/141)
+* Add methods that tell which columns would be affected by a transformer ([#304](https://github.com/Safe-DS/Stdlib/issues/304)) ([3933b45](https://github.com/Safe-DS/Stdlib/commit/3933b458042f524d337f41d0ffa3aa4da16f5a2e)), closes [#190](https://github.com/Safe-DS/Stdlib/issues/190)
+* Getters for hyperparameters of Regression and Classification models ([#306](https://github.com/Safe-DS/Stdlib/issues/306)) ([5c7a662](https://github.com/Safe-DS/Stdlib/commit/5c7a6623cd47f7c6cc25d2cd02179ff5b1a520d9)), closes [#260](https://github.com/Safe-DS/Stdlib/issues/260)
+* improve error handling of table ([#308](https://github.com/Safe-DS/Stdlib/issues/308)) ([ef87cc4](https://github.com/Safe-DS/Stdlib/commit/ef87cc4d7f62fd0830688f8535e53ad7e2329457)), closes [#147](https://github.com/Safe-DS/Stdlib/issues/147)
+* Remove warnings thrown in new `Transformer` methods ([#324](https://github.com/Safe-DS/Stdlib/issues/324)) ([ca046c4](https://github.com/Safe-DS/Stdlib/commit/ca046c40217bebcc05af98129d4e194c0509c9bb)), closes [#323](https://github.com/Safe-DS/Stdlib/issues/323)
+
 ## [0.12.0](https://github.com/Safe-DS/Stdlib/compare/v0.11.0...v0.12.0) (2023-05-11)
 
 

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "safe-ds"
-version = "0.12.0"
+version = "0.13.0"
 description = "A user-friendly library for Data Science in Python."
 authors = ["Lars Reimann <[email protected]>"]
 license = "MIT"
@@ -29,8 +29,8 @@ pytest-cov = "^4.0.0"
 [tool.poetry.group.docs.dependencies]
 jupyter = "^1.0.0"
 mkdocs = "^1.4.2"
-mkdocstrings = ">=0.20,<0.22"
-mkdocstrings-python = ">=0.8.3,<0.10.0"
+mkdocstrings = ">=0.20,<0.23"
+mkdocstrings-python = ">=0.8.3,<1.2.0"
 mkdocs-autorefs = "^0.4.1"
 mkdocs-gen-files = ">=0.4,<0.6"
 mkdocs-glightbox = "^0.3.1"

src/safeds/data/tabular/containers/_table.py

@@ -4,7 +4,7 @@
 import io
 import warnings
 from pathlib import Path
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, TypeVar
 
 import matplotlib.pyplot as plt
 import numpy as np
@@ -795,6 +795,32 @@ def filter_rows(self, query: Callable[[Row], bool]) -> Table:
             result_table = self.from_rows(rows)
         return result_table
 
+    _T = TypeVar("_T")
+
+    def group_by(self, key_selector: Callable[[Row], _T]) -> dict[_T, Table]:
+        """
+        Return a dictionary with the output tables as values and the keys from the key_selector.
+
+        This table is not modified.
+
+        Parameters
+        ----------
+        key_selector : Callable[[Row], _T]
+            A Callable that is applied to all rows and returns the key of the group.
+
+        Returns
+        -------
+        dictionary : dict
+            A dictionary containing the new tables as values and the selected keys as keys.
+        """
+        dictionary: dict[Table._T, Table] = {}
+        for row in self.to_rows():
+            if key_selector(row) in dictionary:
+                dictionary[key_selector(row)] = dictionary[key_selector(row)].add_row(row)
+            else:
+                dictionary[key_selector(row)] = Table.from_rows([row])
+        return dictionary
+
     def keep_only_columns(self, column_names: list[str]) -> Table:
         """
         Return a table with only the given column(s).

tests/safeds/data/tabular/containers/_table/test_group_by.py

@@ -0,0 +1,35 @@
+from collections.abc import Callable
+
+import pytest
+from safeds.data.tabular.containers import Table
+
+
+@pytest.mark.parametrize(
+    ("table", "selector", "expected"),
+    [
+        (
+            Table({"col1": [1, 1, 2, 2, 3], "col2": ["a", "b", "c", "d", "e"]}),
+            lambda row: row["col1"],
+            {
+                1: Table({"col1": [1, 1], "col2": ["a", "b"]}),
+                2: Table({"col1": [2, 2], "col2": ["c", "d"]}),
+                3: Table({"col1": [3], "col2": ["e"]}),
+            },
+        ),
+        (
+            Table({"col1": [1, 1, 2, 2, 3], "col2": ["a", "b", "c", "d", 2]}),
+            lambda row: row["col1"],
+            {
+                1: Table({"col1": [1, 1], "col2": ["a", "b"]}),
+                2: Table({"col1": [2, 2], "col2": ["c", "d"]}),
+                3: Table({"col1": [3], "col2": [2]}),
+            },
+        ),
+        (Table(), lambda row: row["col1"], {}),
+        (Table({"col1": [], "col2": []}), lambda row: row["col1"], {}),
+    ],
+    ids=["select by row1", "different types in column", "empty table", "table with no rows"],
+)
+def test_group_by(table: Table, selector: Callable, expected: dict) -> None:
+    out = table.group_by(selector)
+    assert out == expected