def keys(self) -> pd.Index:
    "\n        Return alias for columns.\n\n        Returns\n        -------\n        Index\n            Columns of the DataFrame.\n\n        Examples\n        --------\n        >>> df = ps.DataFrame([[1, 2], [4, 5], [7, 8]],\n        ...                   index=['cobra', 'viper', 'sidewinder'],\n        ...                   columns=['max_speed', 'shield'])\n        >>> df\n                    max_speed  shield\n        cobra               1       2\n        viper               4       5\n        sidewinder          7       8\n\n        >>> df.keys()\n        Index(['max_speed', 'shield'], dtype='object')\n        "
    return self.columns
Return alias for columns.

Returns
-------
Index
    Columns of the DataFrame.

Examples
--------
>>> df = ps.DataFrame([[1, 2], [4, 5], [7, 8]],
...                   index=['cobra', 'viper', 'sidewinder'],
...                   columns=['max_speed', 'shield'])
>>> df
            max_speed  shield
cobra               1       2
viper               4       5
sidewinder          7       8

>>> df.keys()
Index(['max_speed', 'shield'], dtype='object')
def keys(self) -> pd.Index:
    "\n        Return alias for columns.\n\n        Returns\n        -------\n        Index\n            Columns of the DataFrame.\n\n        Examples\n        --------\n        >>> df = ps.DataFrame([[1, 2], [4, 5], [7, 8]],\n        ...                   index=['cobra', 'viper', 'sidewinder'],\n        ...                   columns=['max_speed', 'shield'])\n        >>> df\n                    max_speed  shield\n        cobra               1       2\n        viper               4       5\n        sidewinder          7       8\n\n        >>> df.keys()\n        Index(['max_speed', 'shield'], dtype='object')\n        "
    return self.columns