规范化pandas中的数据错误

Question

当我尝试在我的jupyter笔记本中运行以下命令时，在规范化数据时会出现问题。代码下面是我收到的错误消息。

代码：

RuntimeWarning: ‘<’ not supported between instances of ‘str’ and ‘float’, sort order is undefined for incomparable objects
 result = result.union(other)

RuntimeWarning: ‘<’ not supported between instances of ‘float’ and ‘str’, sort order is undefined for incomparable objects
 index = _union_indexes(indexes)

错误讯息：

public void clearTxt(WebElement element) throws Exception{
      element.click();
      element.sendKeys(Keys.CONTROL + "A"); //select all
      element.sendKeys(Keys.DELETE);          
}

我认为这与我试图合并两个数据帧的事实有关吗？但我不确定。