Pandas 数据框条件均值

Question

I'm trying to find the average number of cigarettes smoked per day among women who smoked during pregnancy for a given dataset. Currently, I'm trying

mean = data.groupby(['male', 'cigs']).mean()
print(mean)

That gives me the mean average family income for each amount of cigarettes smoked per day (ie 0 per day, 2 per day, 8 per day, ect). How do I get it so it's the average family income for those who smoked >= 1?

Also, this is my first post on stack so forgive me if there isn't enough detail.

Answer 1

I assume " cigs " refers to number of Cigarettes smoked per day. You can first filter the data based on cigs >=1 and then apply what you were doing.

data_on_people_who_smoke = data[data.cigs >= 1]
mean = data_on_people_who_smoke.groupby(['male', 'cigs']).mean()
print(mean)

Answer 2

mean = data[data['cigs']>1]['income'].mean()
print (mean)

This gives you the mean of the income of all respondents that smoke at least 1 cig. don't groupby gender or cigs. Filter first, and get the mean.