I'm a pretty new coder so if you guys could help me that'd be great.

Let's say I have one dataframe:
[![enter image description here](https://i.stack.imgur.com/0TKXG.png)](https://i.stack.imgur.com/0TKXG.png)

Can I combine "Number" and "Number 2" in a way where "Number" takes precedence unless there is no value(NaN). When "Number" is NaN, then we use the entry in "Number 2"

It should look like this [![enter image description here](https://i.stack.imgur.com/UZOpQ.png)](https://i.stack.imgur.com/UZOpQ.png)

In other words, I want to combine "Number" and "Number 2" where if "Number" is NaN, then use "Number 2"'s entry. If "Number" has an entry, keep it for the merged entry. This is similar to left merge for merging two data frames.

Btw, I'm using python and pandas.

Update: trying to use np.where

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

Output without np.where: [![enter image description here](https://i.stack.imgur.com/dAbu2.png)](https://i.stack.imgur.com/dAbu2.png)

Output with np.where: [![enter image description here](https://i.stack.imgur.com/UPhtK.png)](https://i.stack.imgur.com/UPhtK.png)