Hi, I have a question related to this exercise. This course is found in pandas section in data science track.

My question is related to Task 6: Create a new column in `clicks_pivot`

called `percent_clicked`

which is equal to the percent of users who clicked on the ad from each `utm_source`

.

This is my original attempt, and the `percent_clicked`

column showed incorrect result:

(1st method)

```
percent = lambda row: row[True]/(row[False] + row[True])
clicks_pivot["percent_clicked"] = clicks_pivot.apply(percent, axis = 1)
```

A answer before states that lambda function returns an integer, so one should multiply the expression by 100, but it doesn;t work.

The hint in the question is as below:

(2nd method)

```
clicks_pivot['percent_clicked'] = \
clicks_pivot[True] / \
(clicks_pivot[True] +
clicks_pivot[False])
```

Although the second method is intuitive, I am still curious that why doesn’t the first method can’t show the correct result.

Thanks,

Frank