连接字符串时强制转换无法按预期工作

Question

我正在尝试实现最简单的任务-创建如下所示的FISCAL_YEAR列(列YEAR给出):

+------+-------------+
| YEAR | FISCAL_YEAR |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+
| 2022 | 2022-2023   |
+------+-------------+

我一直得到错误:can only concatenate str (not "int") to str

这些是我目前为止尝试过的步骤，没有成功:

1. df['fiscal_year'] = str(df['year']) + "-" + str(df['year']+1)

2. df['fiscal_year'] = df['year'].astype(str) + "-" + (df['year']+1).astype(str)

df['year_str'] = pd.Series(df['year'], dtype=pd.StringDtype())

也:

df['year_str'] = df['year'].astype(str)

然后:

df['year_str'].str.cat(df['year_str'].astype(int) + 1, sep='-')

这些选项都不起作用。我还遗漏了什么吗?

**我在Windows 10和Python版本3.9.7

Answer 1

一个万无一失的方法可能是:

df['FISCAL_YEAR'] = (df['YEAR'].astype(str)
+'-'+
df['YEAR'].astype(int).add(1).astype(str)
)

输出:

YEAR FISCAL_YEAR
0  2022   2022-2023
1  2022   2022-2023
2  2022   2022-2023
3  2022   2022-2023