python - 将数据帧作为类方法返回

Question

我想在创建对象时创建作为数据框的报表对象。该代码旨在读取文件并作为实例化和调用加载方法的一部分进行一些过滤

class Report:
    def __init__(self,c = ['red','green','blue'],y = [2015,2016,2017,2018,2019]):
        self.color = c
        self.years = y

    def load(self):
        df = pd.read_excel(r"C:\Users\ger\Desktop\sample.xlsx",sheet_name='sht1')
        df = df.loc[(df['color'].isin(self.color) & 
                     df['year'].isin(self.years)),:]
        return df

# none of these below seems to work though
r1 = Report().load()

# or
r1 = Report()
r1 = r1.load()

预期结果将是具有颜色和年份字段的数据帧，如 init 中提到的或 Report() 调用中定义的。任何想法都非常感激

Answer 1

如果您的目标是将 load 作为实际的类方法，那么以下是适合您的情况的示例:

import pandas as pd

class Report:
    def __init__(self, c=['red', 'green', 'blue'], y=[2017, 2018, 2019]):
        self.color = c
        self.years = y

    @classmethod
    def load(cls, self):
        df = pd.DataFrame(
            {'color': ['red', 'blue', 'green', 'yellow', 'purple'],
             'year': [2015, 2016, 2017, 2018, 2019]}
        )
        df = df.loc[df['color'].isin(self.color) & df['year'].isin(self.years)]
        self.df = df

实际操作:

>>> report = Report()
>>> Report.load(report)
>>> print(report.df)
   color  year
2  green  2017