python - 纠正不完整的年份 - Python

Question

我在数据框中有一个年份列，它具有独特的值，例如

['2017', '2018', '2019', '2015', '2016', '2011', '2010', '2014',
 '215', '2013', nan, '216', '217', '2008', '218', '219',
 '2012', '211', '2002', '214', '17']

有几年写的不全。比如217代表2017年，17代表2017年等等
是否可以在没有硬编码替换的情况下用正确的年份替换这些值？
我自己搜索了一些解决方案，但没有找到任何有用的东西。

Answer 1

import numpy as np

years = ['2017', '2018', '2019', '2015', '2016', '2011', '2010', '2014',
 '215', '2013', np.nan, '216', '217', '2008', '218', '219',
 '2012', '211', '2002', '214', '17']

corrected_years = ["20" + year[-2:] if year is not np.nan else year for year in years]

输出:

['2017',
 '2018',
 '2019',
 '2015',
 '2016',
 '2011',
 '2010',
 '2014',
 '2015',
 '2013',
 nan,
 '2016',
 '2017',
 '2008',
 '2018',
 '2019',
 '2012',
 '2011',
 '2002',
 '2014',
 '2017']