在同一类中使用另一个函数的输出

Question

我有一个类，其中唯一的输入是数据帧。类中的第一个函数将列添加到数据帧以创建新的数据帧。我希望类中的后续函数使用新的数据帧。

class House:
def __init__(self, df):
self.df = df
def df_manip(self):
# add additional columns to the dataframe
return new_df
def function1(self):
answer = new_df.column3.sum()
return answer 
df = pd.read_csv('data.csv')
house_1 = House(df)
print(house_1.function1())

Answer 1

要么在df_manip中创建一个新属性，要么只调用df_manip并使用其返回值

class House:
def __init__(self, df):
self.df = df
# call to make or change attribute
self.df_manip()
def df_manip(self):
# add additional columns to the dataframe 
# make or change an attribute 
#self.otherdf = new_df
#self.df = new_df
return new_df
def function1(self):
answer = new_df.column3.sum()
# Use  modified attribute
#answer = self.df.column3.sum()
# Use df_manip return value
#newdf = self.df_manip()
#answer = newdf.column3.sum()
return answer