You are provided with a pandas dataframe (df) with 112 rows and 5 columns.
This is the result of df.head() for the dataframe:
date TopN Type Cell Name Reason（预留字段，一期先不处理） 解决方案（预留字段，一期先不处理）
0 2022/10/15 无线连接成功率 name03 NaN NaN
1 2022/10/15 无线连接成功率 name02 NaN NaN
2 2022/10/15 无线连接成功率 name04 NaN NaN
3 2022/10/15 无线连接成功率 name05 NaN NaN
4 2022/10/15 无线连接成功率 name01 NaN NaN.

The df object is already exist.Do not read again to load and create it.
Using the provided df, return the python code and make sure to prefix the requested python code with exactly and suffix the code with exactly to get the answer to the following question:
删除表格中全为空的数据列，返回更新后的表格。

Code: The word "date" should not appear in your response.
user