减去两个datetime以获取天数（python） [英] Subtract two datetime to get the number of days (python)

问题描述

在过去的两天里，我一直在思考这个问题，而我正处于放弃的边缘。

I have been wrapping my mind around this for the last two days, and I am on the verge of giving up.

我有一个名为 Renewed_subscription 的列，格式为 datetime 。我需要确定从今天到一个人必须续订订阅的日期之间有多少天。

I have a col named Renewed_subscription, format datetime. I need to get how many days are between today and the date when a person has to renew his subscription.

from datetime import datetime
dataset['DaysUntilSub'] = dataset.apply(lambda x: (pd.Timestamp.today().strftime('%Y-%m-%d') - str(dataset['Renewed_subscription'])).days, axis=1)

它抛出错误：

TypeError跟踪（最近一次通话）

TypeError Traceback (most recent call last)

C：\Report.py in（）

C:\Report.py in ()

-> 166数据集['DaysUntilSub'] =数据集.apply（lambda x：（pd.Timestamp.today（）。strftime（'％Y-％m-％d '）-str（dataset ['Renewed_subscription']）。days，axis = 1）

--> 166 dataset['DaysUntilSub'] = dataset.apply(lambda x: (pd.Timestamp.today().strftime('%Y-%m-%d') - str(dataset['Renewed_subscription'])).days, axis=1)

168 #dataset ['DaysUntilSub'] = dataset.apply（lambda x ：（pd.Timestamp.today（）。strftime（'％Y-％m-％d'）-str（dataset ['Renewed_subscription']））。days，axis = 1）

168 #dataset['DaysUntilSub'] = dataset.apply(lambda x: (pd.Timestamp.today().strftime('%Y-%m-%d') - str(dataset['Renewed_subscription'])).days, axis=1)

C：\用户\katep\Anaconda3\lib\站点包\pandas\core\frame.py in apply（self，func，axis，broa dcast，raw，reduce，args，** kwds）

C:\Users\katep\Anaconda3\lib\site-packages\pandas\core\frame.py in apply(self, func, axis, broadcast, raw, reduce, args, **kwds)

4150如果reduce为None：
4151 reduce = True
-> 4152 return self ._apply_standard（f，axis，reduce = reduce）
4153 else：
4154 return self._apply_broadcast（f，axis）

4150 if reduce is None: 4151 reduce = True -> 4152 return self._apply_standard(f, axis, reduce=reduce) 4153 else: 4154 return self._apply_broadcast(f, axis)

C：＼ ＼用户\katep\Anaconda3\lib站点包\熊猫\核心\frame.py in _apply_standard（自我，函数，轴，ignore_failures，reduce）

C:\Users\katep\Anaconda3\lib\site-packages\pandas\core\frame.py in _apply_standard(self, func, axis, ignore_failures, reduce)

4246尝试：

4247 for i，v in enumerate（series_gen）：

4247 for i, v in enumerate(series_gen):

- > 4248个结果[i] = func（v）

-> 4248 results[i] = func(v)

4249 keys.append（v.name）

4249 keys.append(v.name)

4250例外，例如e：

4250 except Exception as e:

C：\Report.py in（x）

C:\Report.py in (x)

TypeError：（ -的不支持的操作数类型：'str'和'str'，出现在索引42'）

TypeError: ("unsupported operand type(s) for -: 'str' and 'str'", 'occurred at index 42')

如果您能指出我的错误，我将不胜感激，因为我不能因此而继续分析！

I will be very grateful if you could, please, point at my error, because I cannot proceed with the analysis because of it!

推荐答案

如上所述，您不想在减去之前将 datetime 转换为字符串。您可以使用简单的-符号进行操作，然后查找多少天。

As above mentioned, you don't want to cast datetime to string before subtraction. You can operate using simple - sign and find how many days later.

from datetime import datetime
import pandas as pd

# create example dataframe
df = pd.DataFrame([datetime(1985, 4, 10), 
                   datetime(2010, 4, 10), 
                   datetime(2015, 4, 10), 
                   datetime(2017, 4, 10)], columns=['Renewed_subscription'])
# subtraction with today
df['DaysUntilSub'] = df['Renewed_subscription'].map(lambda x: (datetime.today() - x).days)

数据帧溢出

  Renewed_subscription  DaysUntilSub
0   1985-04-10  11695
1   2010-04-10  2564
2   2015-04-10  738
3   2017-04-10  7

同样的解决方案没有lambda：

And the same solution without a lambda:

def days_from_today(date):
    return (datetime.today() - date).days

df['DaysUntilSub'] = df['Renewed_subscription'].map(days_from_today)

这篇关于减去两个datetime以获取天数（python）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！