两列的 Groupby 合计百分比

Question

I have a DataFrame:

df = pd.DataFrame({
    'Product': ['AA', 'AA', 'AA', 'AA', 'BB', 'BB', 'BB', 'BB'],
    'Type': ['AC', 'AC', 'AD', 'AD', 'BC', 'BC', 'BD', 'BD'],
    'Sales': [ 200, 100, 400, 100, 300, 100, 200, 500], 
    'Qty': [ 5, 3, 3, 6, 4, 7, 4, 1]})

I want to try and get the percentage of total by "Product" and "Type" for both "Sales" and "Qty". I can get the percentage of total for "Sales" and "Qty" separately. But I was wondering if there was a way of doing so for both columns.

To get the percentage of total for one column, the code is:

df['Sales'] = df['Sales'].astype(float)
df['Qty'] = df['Qty'].astype(float)
df = df[['Product', 'Type', 'Sales']]

df = df.groupby(['Product', 'Type']).agg({'Sales': 'sum'})
pcts = df.groupby(level= [0]).apply(lambda x: 100 * x / float(x.sum()))

Is there a way of get this for both columns in one go?

Answer 1

You can chain groupby :

pct = lambda x: 100 * x / x.sum()

out = df.groupby(['Product', 'Type']).sum().groupby('Product').apply(pct)
print(out)

# Output
                  Sales        Qty
Product Type                      
AA      AC    37.500000  47.058824
        AD    62.500000  52.941176
BB      BC    36.363636  68.750000
        BD    63.636364  31.250000

Answer 2

You could groupby "Product" and "Type" get the totals for each group. Then groupby "Product" (which is level=0) again and transform sum ; then divide the sum from the previous step with it:

sm = df.groupby(['Product','Type']).sum()
out = sm / sm.groupby(level=0).transform('sum') * 100

Output:

                  Sales        Qty
Product Type                      
AA      AC    37.500000  47.058824
        AD    62.500000  52.941176
BB      BC    36.363636  68.750000
        BD    63.636364  31.250000

Answer 3

One option is to get the values from individual groupbys and divide:

numerator = df.groupby(["Product", "Type"]).sum()
denominator = df.groupby("Product").sum()
numerator.div(denominator, level = 0, axis = 'index') * 100

                  Sales        Qty
Product Type                      
AA      AC    37.500000  47.058824
        AD    62.500000  52.941176
BB      BC    36.363636  68.750000
        BD    63.636364  31.250000