我需要比较和日期并返回还有多少天到期或多少天前到期

Question

我以前从未使用过 Python，来自 Javascript 背景。

我需要遍历 csv 中的数组并将其与 today 变量中的日期进行比较。然后返回每个项目过期或有效的位置。还有还有多少天要到期或到期前多少天。

任何指针？

from datetime import datetime

today = datetime(2020, 5, 2)

with open('./guarantees_end.csv', 'r') as f: 
    for line in f.readlines():

我的 csv 数据编译如下：

2020-06-23,Flat C

2020-07-31,2 Teal Close

2020-08-14,67 Pinkers Mead

2020-08-31,3 Acacia Road

2020-04-13,1 Manor Place

Answer 1

您可以使用以下方式读取今天的日期：

import datetime    
today = datetime.datetime.now().date()

我的 temp.csv 包含：

2020-12-11, ABCD
2020-12-23, EFGH
2020-12-01, IJKL
2020-11-11, MNOP

要从 CSV 读取，您可以使用：

f = open('temp.csv')
csv_reader = csv.reader(f, delimiter=',')
for row in csv_reader:
    product_date_str = str(row[0])

现在您可以使用以下方法将日期字符串（从 csv 读取）转换为 datetime.date 对象：

date_format = '%Y-%m-%d'
product_date = datetime.datetime.strptime(product_date_str, date_format).date()

现在您可以使用以下方法获取日期差异：

diff = (today - product_date).days

然后您可以使用此差异来打印或显示您想要的任何内容。例如：

if diff > 0:
    print('{} has already expired since {} days.'.format(row[1], abs(diff)))
elif diff < 0:
    print('{} will expire in next {} days.'.format(row[1], abs(diff)))
else:
    print('{} will expire today.'.format(row[1]))

所以完整的代码 sn-p 看起来像：

import  csv
import datetime

today = datetime.datetime.now().date()
with open('temp.csv') as f:
    csv_reader = csv.reader(f, delimiter=',')
    for row in csv_reader:
        product_date_str = str(row[0])
        date_format = '%Y-%m-%d'
        product_date = datetime.datetime.strptime(product_date_str, date_format).date()
        diff = (today - product_date).days
        if diff > 0:
            print('{} has already expired since {} days.'.format(row[1], abs(diff)))
        elif diff < 0:
            print('{} will expire in next {} days.'.format(row[1], abs(diff)))
        else:
            print('{} will expire today.'.format(row[1]))