Средний из всех рядов панды
df.mean(axis=0)#average for each column
df.mean(axis=1)#average for each row
Cashecode
df.mean(axis=0)#average for each column
df.mean(axis=1)#average for each row
df['mean'] = df.iloc[:, 0:4].mean(axis=1)
df['mean'] = df.iloc[:, [0,1,2,3,4].mean(axis=1)