Python：函数名称的字符串，它如何工作？

数据框将覆盖__getattr__以连接到属性解析。这允许从返回任意对象df.anything。该实例在中维护“真实”属性名称的内部列表，self._internal_names_set并在中维护列名称的列表self._info_axis。

def __getattr__(self, name):
    """After regular attribute access, try looking up the name
    This allows simpler access to columns for interactive use.
    """

    # Note: obj.x will always call obj.__getattribute__('x') prior to
    # calling obj.__getattr__('x').

    if (name in self._internal_names_set or name in self._metadata or
            name in self._accessors):
        return object.__getattribute__(self, name)
    else:
        if name in self._info_axis:
            return self[name]
        return object.__getattribute__(self, name)

来源在这里。