Python pandas 从数据框中获取值并存储在对象中

Question

给定以下 pandas 数据框，我如何创建一个对象数组，其中包含年份介于 2020 和 2015 之间的行中的所有值？假设数据框中包含 2020 年到 2010 年的数据。

    Year  Yield     Total   Amount      ExDate     PayDate  \
0   2020  3.09%  SGD 0.66  SGD0.33  2020-05-12  2020-05-26   
1   2020  3.09%  SGD 0.66  SGD0.33  2020-05-12  2020-05-26   
2   2019  7.02%   SGD 1.5   SGD0.3  2019-11-18  2019-11-29   
3   2019  7.02%   SGD 1.5   SGD0.3  2019-08-05  2019-08-20   
4   2019  7.02%   SGD 1.5   SGD0.3  2019-05-17  2019-05-31   
5   2019  7.02%   SGD 1.5   SGD0.6  2019-05-02  2019-05-17   
6   2018  7.95%   SGD 1.7   SGD0.6  2018-08-08  2018-08-21   
7   2018  7.95%   SGD 1.7   SGD0.6  2018-05-03  2018-05-15   
8   2018  7.95%   SGD 1.7   SGD0.5  2018-05-03  2018-05-15   
9   2017  2.95%  SGD 0.63  SGD0.33  2017-08-11  2017-09-27

对象：

class Object:
  def__init(self, year, yield_data, amount, total, ex_date, pay_date):
    self.year = year
    self. yield_data = yield_data
    self.total = total
    self.ex_date = ex_date
    self.pay_date = pay_date
    self.amount = amount

Answer 1

让我们试试这个，Series.between to filter the records between year's followed by DataFrame.drop_duplicates 获取唯一的行，然后是 DataFrame.rename 根据构造函数参数的列，用于稍后在对象构造期间解包。

rename_cols = {'Year': 'year', 'Yield': 'yield_data', 'Amount': 'amount',
               'Total': 'total', 'ExDate': 'ex_date', 'PayDate': 'pay_date'}

data = (
    df[df.Year.between(2015, 2020)].drop_duplicates(subset=['Year']).
        rename(columns=rename_cols).to_dict(orient='records')
)

object_list = [Object(**x) for x in data]

for obj in object_list:
    print(f"Year : {obj.year}, Yield {obj.yield_data}")

Year : 2020, Yield 3.09%
Year : 2019, Yield 7.02%
Year : 2018, Yield 7.95%
Year : 2017, Yield 2.95%

Python pandas 从数据框中获取值并存储在对象中

Python pandas get value from dataframe and store in object

python

python-3.x

pandas

python-3.7