How to get count of rows and sum of number of a column for all the groups in a pandas dataframe?

I have a pandas dataframe-

import pandas as pd
df = pd.DataFrame([["tv", 10], ["mobile", 5], ["tv", 0], ["mobile", 100]])
df.columns = ["device", "sale"]

It looks like-

    device  sale
0   tv      10
1   mobile  5
2   tv      0
3   mobile  100

I want to apply groupby on device column and find the number of rows and sum of sale column for every group

The desired output should like like-

    device  count sum_sale
0   tv      2     10
1   mobile  2     105

How do I achieve this?