# How to do a calculation based off a T/F condition in a Pandas DataFrame

So I am really not sure how I should go about this. I am working with pandas in python. I have a csv file I converted into a data frame called `df`

. I have this column:

```
Is_High_School
FALSE
FALSE
FALSE
TRUE
FALSE
...
```

And I have another column:

```
Student_Count
454
343
213
223
676
...
```

I want to calculate the mean and stdev of the student count, but only where `Is_High_School`

is FALSE.

May I get some direction with how to approach this? I have tried the `df.where()`

, and it isn't working for me because I get NaN, and I don't know how to propagate that so that I can calculate in another column only where that condition is met. Thanks, I really appreciate it.

edit:

I created a smaller dataframe called hs. Here it is:

```
dataframe: Is_High_School Student_Count_Total
0 False 415
1 False 241
2 False 346
3 False 91
4 False 248
.. ... ...
655 False 509
656 False 507
657 True 341
658 True 1086
659 True 1308
```

## Answers 1

Just filter your dataframe according to the condition is required then calculate it.