Summary  
The chapter explains how to use pandas DataFrame methods `max()` and `min()` to retrieve the highest and lowest values from an entire dataset or a specific column.  

General domain of usage  
Data analysis

`pandas` には `max()` メソッドがあり、データセットから**最大値**を返します。

```python
df = pd.read_csv(file.csv)
max_value = df.max()
```

特定の列の最大値を取得するには、次の方法を使用します：
```python
df = pd.read_csv(file.csv)
max_values = df['column_name'].max()
```

同様に、`pandas` には `min()` メソッドがあり、データセットから**最小値**を取得します。
```python
df = pd.read_csv(file.csv)
min_value = df.min()
```

特定の列の最小値を求める場合も、同じ方法を使用：
```python
df = pd.read_csv(file.csv)
min_values = df['column_name'].min()
```

import unittest
import importlib


def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)


class TestUserCode(unittest.TestCase):

    def test_highest_price_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'highest_price'),
            "The `highest_price` variable is declared.",
            "Expected `highest_price` to be declared."
        )

    def test_highest_price_is_correct(self):
        import user_code
        expected_value = max([12500, 16500, 16800, 17300, 16500])

        try:
            actual_value = user_code.highest_price
            condition = actual_value == expected_value
            failure_message = f"Expected `highest_price` to be `{expected_value}`, but got `{actual_value}`."
        except AttributeError:
            condition = False
            failure_message = "The `highest_price` variable is not declared."

        _dynamic_test(
            self,
            condition,
            f"The `highest_price` is `{expected_value}`.",
            failure_message
        )

    def test_lowest_price_is_declared(self):
        import user_code
        _dynamic_test(
            self,
            hasattr(user_code, 'lowest_price'),
            "The `lowest_price` variable is declared.",
            "Expected `lowest_price` to be declared."
        )

    def test_lowest_price_is_correct(self):
        import user_code
        expected_value = min([12500, 16500, 16800, 17300, 16500])

        try:
            actual_value = user_code.lowest_price
            condition = actual_value == expected_value
            failure_message = f"Expected `lowest_price` to be `{expected_value}`, but got `{actual_value}`."
        except AttributeError:
            condition = False
            failure_message = "The `lowest_price` variable is not declared."

        _dynamic_test(
            self,
            condition,
            f"`lowest_price` has correct value.",
            failure_message
        )


if __name__ == '__main__':
    unittest.main()

test_main.py

pandasを使用した実践的なデータ操作スキルの習得。SeriesおよびDataFrameの操作、データセットの読み込みと探索、データの選択とフィルタリング、集約処理、テーブルの再構成、複数のDataFrameの結合、分析のためのデータ準備。

max() と min()

解答