當列中已存在多種日期格式時，更改整個 Dataframe 列的日期格式？

Question

bond_df['Maturity']

0     2022-07-15 00:00:00
1     2024-07-18 00:00:00
2     2027-07-16 00:00:00
3     2020-07-28 00:00:00
4     2019-10-09 00:00:00
5     2022-04-08 00:00:00
6     2020-12-15 00:00:00
7     2022-12-15 00:00:00
8     2026-04-08 00:00:00
9     2023-04-11 00:00:00
10    2024-12-15 00:00:00
11                   2019
12    2020-10-25 00:00:00
13    2024-04-22 00:00:00
14    2047-12-15 00:00:00
15    2020-07-08 00:00:00
17    2043-04-11 00:00:00
18                   2021
19                   2022
20                   2023
21                   2025
22                   2026
23                   2027
24                   2029
25    2021-04-15 00:00:00
26    2044-04-22 00:00:00
27    2043-10-02 00:00:00
28    2039-01-19 00:00:00
29    2040-07-09 00:00:00
30    2029-09-21 00:00:00
31    2040-10-25 00:00:00
32                   2019
33    2035-09-04 00:00:00
34    2035-09-28 00:00:00
35    2041-04-15 00:00:00
36    2040-04-02 00:00:00
37    2034-03-27 00:00:00
38                   2030
39    2027-04-05 00:00:00
40    2038-04-15 00:00:00
41    2037-08-17 00:00:00
42    2023-10-16 00:00:00
43                      -
45    2019-10-09 00:00:00
46                      -
47    2021-06-23 00:00:00
48    2021-06-23 00:00:00
49    2023-06-26 00:00:00
50    2025-06-26 00:00:00
51    2028-06-26 00:00:00
52    2038-06-28 00:00:00
53    2020-06-23 00:00:00
54    2020-06-23 00:00:00
55    2048-06-29 00:00:00
56                      -
57                      -
58    2029-07-08 00:00:00
59    2026-07-08 00:00:00
60    2024-07-08 00:00:00
61    2020-07-31 00:00:00
Name: Maturity, dtype: object

這是我從 Excel 導入的關於各種沃爾瑪債券到期日的數據列。 我只關心這些日期的年份部分。 如何格式化整個列以僅返回年份值？

dt.strftime 沒有工作

提前致謝

Answer 1

為您編寫了這個小腳本，它應該 output 在 years.txt 文件中的年份，假設您的數據在 data.txt 中，就像您在上面發布的年份一樣。

如果要在右側包含破折號和年份，腳本還允許您切換。

我測試的data.txt的內容：

0     2022-07-15 00:00:00
1     2024-07-18 00:00:00
2     2027-07-16 00:00:00
3     2020-07-28 00:00:00
4     2019-10-09 00:00:00
5     2022-04-08 00:00:00
6     2020-12-15 00:00:00
7     2022-12-15 00:00:00
8     2026-04-08 00:00:00
9     2023-04-11 00:00:00
10    2024-12-15 00:00:00
11                   2019
12    2020-10-25 00:00:00
13    2024-04-22 00:00:00
14    2047-12-15 00:00:00
15    2020-07-08 00:00:00
17    2043-04-11 00:00:00
18                   2021
19                   2022
20                   2023
21                   2025
22                   2026
23                   2027
24                   2029
25    2021-04-15 00:00:00
26    2044-04-22 00:00:00
27    2043-10-02 00:00:00
28    2039-01-19 00:00:00
29    2040-07-09 00:00:00
30    2029-09-21 00:00:00
31    2040-10-25 00:00:00
32                   2019
33    2035-09-04 00:00:00
34    2035-09-28 00:00:00
35    2041-04-15 00:00:00
36    2040-04-02 00:00:00
37    2034-03-27 00:00:00
38                   2030
39    2027-04-05 00:00:00
40    2038-04-15 00:00:00
41    2037-08-17 00:00:00
42    2023-10-16 00:00:00
43                      -
45    2019-10-09 00:00:00
46                      -
47    2021-06-23 00:00:00
48    2021-06-23 00:00:00
49    2023-06-26 00:00:00
50    2025-06-26 00:00:00
51    2028-06-26 00:00:00
52    2038-06-28 00:00:00
53    2020-06-23 00:00:00
54    2020-06-23 00:00:00
55    2048-06-29 00:00:00
56                      -
57                      -
58    2029-07-08 00:00:00
59    2026-07-08 00:00:00
60    2024-07-08 00:00:00
61    2020-07-31 00:00:00

和我寫的腳本：

#!/usr/bin/python3
all_years = []
include_dash = False
include_years_on_right = True
with open("data.txt", "r") as f:
    text = f.read()
    lines = text.split("\n")

for line in lines:
    line = line.strip()
    if line == "":
        continue
    if "00" in line:
        all_years.append(line.split("-")[0].split()[-1])
    else:
        if include_years_on_right == False:
            continue
        year = line.split(" ")[-1]
        if year == "-":
            if include_dash == True:
                all_years.append(year)
            else:
                continue
        else:
            all_years.append(year)
with open("years.txt", "w") as f:
    for year in all_years:
        f.write(year + "\n")

和output到years.txt：

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當列中已存在多種日期格式時，更改整個 Dataframe 列的日期格式？

問題描述

1 個解決方案

解決方案1
0 2020-04-07 19:01:42

當列中已存在多種日期格式時，更改整個 Dataframe 列的日期格式？

問題描述

1 個解決方案

解決方案1 0 2020-04-07 19:01:42

解決方案1
0 2020-04-07 19:01:42