I am doing kind of research and need to delete the raws containing some values which are not in a specific range using Python.

**My Dataset in Excel:**

[![enter image description here](https://i.stack.imgur.com/tvE7U.png)](https://i.stack.imgur.com/tvE7U.png)

1. I want to replace the big values of column A (not within range 1-20) with NaN. Replace Big values of column B (not within range 21-40) and so on.
2. Now I want to drop/ delete the raws contains the NaN values

**Expected output should be like:**

[![enter image description here](https://i.stack.imgur.com/uJDLa.png)](https://i.stack.imgur.com/uJDLa.png)